Category Archives: USDM

Oil Additives: What Subaru Says

Oil Additives: What Subaru Says

Subaru of America does not recommend the use of any engine oil additives in any Subaru engine crankcase. Subaru engines are designed to be lubricated with normal petroleum or synthetic-based engine oils in the viscosity and grade indicated in the Owner’s Manual for each specific engine and usage condition. Subaru has not tested the effectiveness or compatibility of any engine oil additives.

Oil Additive: Avoid adding any oil additives to your Subaru boxer engine.
Oil Additive: Avoid adding any oil additives to your Subaru boxer engine.

However, the use of such oil additives does not void warranty coverage. Usage of any additive is at the owner’s discretion. Since Subaru has not tested the compatibility or effectiveness of any such additives, should an engine failure occur that is determined to be caused by the incompatibility or performance of such an additive, the vehicle owner would be be referred to the additive manufacturer to request reimbursement of the cost of the repair.

If you are using oil additives to try to save a leaking headgasket it’s better to just suck it up and just either install new headgaskets yourself or have the work done by a trusted mechanic.

Either use Subaru’s OEM synthetic motor oil or use Rotella T6 motor oil. If your Subaru is still under warranty by Subaru it’s best to get your oil changed by a Subaru dealership and avoid introducing oil additives into your boxer engine. Even if it’s Subaru’s official stance that they won’t void warranties if oil additives are involved it doesn’t mean that they won’t if there is more evidence of engine “tampering”. Avoid anything that could potentially cause a dealership to refuse service to your car in the future.

Otherwise you might have a expensive repair bill if your Subaru boxer engine spins a bearing or has a ringland failure. Of course adding aftermarket parts like an exhaust or intake along with a tune will greatly increase the justification of a Subaru dealership to void a warranty more than adding oil additives.

Not adding oil additives can be another step in avoiding a void warranty from Subaru of America. On a final note remember that Subaru can scan your ECU for previous tunes even if you went back to a stock tune and will void a warranty for that.

Ignition Coil Testing “Waste spark ignition system”:

Ignition Coil Testing “Waste spark ignition system”:

All late model Subaru four cylinder engines employ a “waste spark” ignition coil system. Each time the ignition coil fires, it provides a spark to two cylinders at exactly the same time. Since only one of the two cylinders is on the compression stroke when the coil fires, the spark to the second cylinder (which is on the exhaust stroke) is “wasted. ”

Ignition Coil Testing "Waste spark ignition sytem": A subaru waste spark coil pack.
Ignition Coil Testing “Waste spark ignition sytem”: A subaru waste spark coil pack.

The ignition coil sits on top of the intake manifold and is divided into two halves. One half provides the spark to the number 1 and 2 cylinders, and the other half provides the spark to the number 3 and 4 cylinders. Instead of the familiar single secondary coil terminal, this coil has four secondary coil terminals.

Testing methods for this type of coil are slightly different from what you might be accustomed to as well. Using an accurate DMM, inspect the following items, and replace the ignition coil if it is found to be defective:

• Primary resistance

• Secondary resistance

Caution: If the resistance is extremely low, this indicates the presence of a short circuit.

Subaru OBD-2 Diagnostic Trouble Codes:

Subaru OBD-2 Diagnostic Trouble Codes:

This is a list of the OBD-2 diagnostic trouble codes for Subaru Impreza, WRX, STi, Forester, and Legacy.

Subaru OBD2 Diagnostic port
Subaru OBD2 Diagnostic port

P0031 Front oxygen (A/F) sensor heater circuit low input
P0032 Front oxygen (A/F) sensor heater circult high input
P0037 Rear oxygen sensor heater circuit malfunction
P0038 Rear oxygen sensor heater circuit high input
P0065 Air assist injector solenoid valve malfunction
P0066 Air assist injector solenoid valve circuit low input
P0067 Air assist injector solenoid valve circuit high input
P0100 Mass or Volume Air Flow Circuit Malfunction
P0101 Mass or Volume Air Flow Circuit Range/Performance Problem
P0102 Mass or Volume Air Flow Circuit Low Input
P0103 Mass or Volume Air Flow Circuit High Input
P0104 Mass or Volume Air Flow Circuit Intermittent
P0105 Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction
P0106 Manifold Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem
P0107 Manifold Absolute Pressure/Barometric Pressure Circuit Low Input
P0108 Manifold Absolute Pressure/Barometric Pressure Circuit High Input
P0109 Manifold Absolute Pressure/Barometric Pressure Circuit Intermittent
P0109 Intake Air Temperature Circuit Malfunction
P0111 Intake Air Temperature Circuit Range/Performance Problem
P0112 Intake Air Temperature Circuit Low Input
P0113 Intake Air Temperature Circuit High Input
P0114 Intake Air Temperature Circuit Intermittent
P0115 Engine Coolant Temperature Circuit Malfunction
P0116 Engine Coolant Temperature Circuit Range/Performance Problem
P0117 Engine Coolant Temperature Circuit Low Input
P0118 Engine Coolant Temperature Circuit High Input
P0119 Engine Coolant Temperature Circuit Intermittent
P0120 Throttle/Petal Position Sensor/Switch A Circuit Malfunction
P0121 Throttle/Petal Position Sensor/Switch A Circuit Range/Performance Problem
P0122 Throttle/Petal Position Sensor/Switch A Circuit Low Input
P0123 Throttle/Petal Position Sensor/Switch A Circuit High Input
P0124 Throttle/Petal Position Sensor/Switch A Circuit Intermittent
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
P0126 Insufficient Coolant Temperature for Stable Operation
P0128 Thermostat malfunction
P0130 O2 Sensor Circuit Malfunction (Bank 1 Sensor 1)
P0131 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 1)
P0132 O2 Sensor Circuit High Voltage (Bank 1 Sensor 1)

P0133 O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)

P0134 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 1)
P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0136 O2 Sensor Circuit Malfunction (Bank 1 Sensor 2)
P0137 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 2)
P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0140 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
P0141 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0142 O2 Sensor Circuit Malfunction (Bank 1 Sensor 3)
P0143 O2 Sensor Circuit Low Voltage (Bank 1 Sensor 3)
P0144 O2 Sensor Circuit High Voltage (Bank 1 Sensor 3)
P0145 O2 Sensor Circuit Slow Response (Bank 1 Sensor 3)
P0146 O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 3)
P0147 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 3)
P0150 O2 Sensor Circuit Malfunction (Bank 2 Sensor 1)
P0151 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 1)
P0152 O2 Sensor Circuit High Voltage (Bank 2 Sensor 1)
P0153 O2 Sensor Circuit Slow Response (Bank 2 Sensor 1)
P0154 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 1)
P0155 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0156 O2 Sensor Circuit Malfunction (Bank 2 Sensor 2)
P0157 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 2)
P0158 O2 Sensor Circuit High Voltage (Bank 2 Sensor 2)
P0159 O2 Sensor Circuit Slow Response (Bank 2 Sensor 2)
P0160 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)
P0161 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)
P0162 O2 Sensor Circuit Malfunction (Bank 2 Sensor 3)
P0163 O2 Sensor Circuit Low Voltage (Bank 2 Sensor 3)
P0164 O2 Sensor Circuit High Voltage (Bank 2 Sensor 3)

P0165 O2 Sensor Circuit Slow Response (Bank 2 Sensor 3)
P0166 O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 3)
P0167 O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 3)
P0170 Fuel Trim Malfunction (Bank 1)
P0171 System too Lean (Bank 1)
P0172 System too Rich (Bank 1)
P0173 Fuel Trim Malfunction (Bank 2)
P0174 System too Lean (Bank 2)
P0175 System too Rich (Bank 2)
P0176 Fuel Composition Sensor Circuit Malfunction
P0177 Fuel Composition Sensor Circuit Range/Performance
P0178 Fuel Composition Sensor Circuit Low Input
P0179 Fuel Composition Sensor Circuit High Input
P0180 Fuel Temperature Sensor A Circuit Malfunction
P0181 Fuel Temperature Sensor A Circuit Range/Performance

P0182 Fuel Temperature Sensor A Circuit Low Input
P0183 Fuel Temperature Sensor A Circuit High Input
P0184 Fuel Temperature Sensor A Circuit Intermittent
P0185 Fuel Temperature Sensor B Circuit Malfunction
P0186 Fuel Temperature Sensor B Circuit Range/Performance
P0187 Fuel Temperature Sensor B Circuit Low Input
P0188 Fuel Temperature Sensor B Circuit High Input
P0189 Fuel Temperature Sensor B Circuit Intermittent
P0190 Fuel Rail Pressure Sensor Circuit Malfunction
P0191 Fuel Rail Pressure Sensor Circuit Range/Performance
P0192 Fuel Rail Pressure Sensor Circuit Low Input
P0193 Fuel Rail Pressure Sensor Circuit High Input
P0194 Fuel Rail Pressure Sensor Circuit Intermittent
P0195 Engine Oil Temperature Sensor Malfunction
P0196 Engine Oil Temperature Sensor Range/Performance
P0197 Engine Oil Temperature Sensor Low
P0198 Engine Oil Temperature Sensor High
P0199 Engine Oil Temperature Sensor Intermittent

Valve Cover Gasket replacement Subaru WRX:

Valve Cover Gasket replacement Subaru WRX:

This is a step by step guide on replacing the valve cover gasket on Subaru flat four engines. This guide will work for most Subaru turbo cars 02-07+ and most other naturally aspirated Subaru cars.

1.) Jack your car up and drain the oil. Remember to put the car on jack stands. You don’t want the car dropping on you.A lot of people do this job with the oil still in the pan, but its better to rather play it safe and drain the oil completely.

2.) Remove the front air scoop. It takes two 10mm bolts.

3.) Remove the nice Cold Air intake box.

4.) After removing all that, you should see this a total of 8 outer bolts and the 2 inner which holds the spark plug coils.

Valve cover gasket: In the center are the two coil packs that need to be removed.
Valve cover gasket: In the center are the two coil packs that need to be removed.

5.) Unscrew them and label them. You don’t want the bolts going into the wrong place. It was a very hard to get any decent clearance so take your time.

Oil pan removal and install on Subaru STi/WRX:

Oil pan removal Subaru STi/WRX:

This is a step by step guide on removing and re-installing a oil pan on your Subaru Impreza STi or WRX. This guide is also useful for installing a STi spec oil pan onto your WRX. This guide also is helpful if you are removing your stock oil pickup tube that is known to crack on the STi. I suggest purchasing a Killer B Motorsport Pickup Tube along with a brand new STi oil pan. Both can be purchased from down below from Amazon.

Brand new STi oil pan:

Subaru 11109AA131 Oil Pan

Killer B Motorsport Pickup Tube:

Killer B Motorsport Subaru Oil Pan Pickup Tube for EJ25 WRX/STI

 

Oil Pan Removal Steps:

1) Remove the plastic under tray from your engine. This is secured using a few bolts and plastic push clips.

2) Remove the plastic under trays from either side of the car, the long ones.

Oil pan removal and install: Remove plastic to gain access to the bottom of the engine.
Oil pan removal and install: Remove plastic to gain access to the bottom of the engine.

3) Remove the jacking plate. This is held on by 2 12mm bolts with nuts in the front, 2 12mm bolts in the rear and 4 14mm nuts on the sides.

4) Remove your subframe. This is secured by a few 19mm bolts, 2 12mm bolts in front and 4 14mm bolts. I highly recommend soaking these all in your PB blaster and waiting 5 minutes. Check out some of my other posts for instuctions.

5) Remove the front oxygen sensor. The correct way is to unplug the clip, unhook it from the metal mount and then pull the wire through the fender-well so that the wire isn’t being stretched and twisted as you unscrew it.

O2 sensor location in the exhaust manifold.
O2 sensor location in the exhaust manifold.

ALK (Anti-Lift Kit) install on 02-07 Subaru WRX/STi:

ALK (Anti-Lift Kit)install on 02-07 Subaru WRX/STi:

This is a step by step guide on how to install a Anti-Lift Kit (ALK) onto a 02-07 WRX/STi. These ALK (Anti-Lift Kits) are designed to be used with the STi’s aluminum control arms.

1.) First unpackage your Anti-Lift Kit (ALK) it’ll look something like this.

Anti-Lift Kit (ALK): This is all the components you'll get with this kit.
Anti-Lift Kit (ALK): This is all the components you’ll get with this kit.

2.)  Get your tools ready and mount the car up properly on jack stands to prevent the car falling down on you. Get as much clearance as you can as you’ll need a lot of room to work with.

Anti-Lift Kit (ALK): Get the front of your STi up on jack stands.
Anti-Lift Kit (ALK): Get the front of your STi up on jack stands.

3.) Make sure you have a decent breaker bar. I’ve destroyed a breaker bar doing this before. Do not use a 3/8 inch drive. Use a 1/2 inch drive so you don’t break a breaker bar and a socket.

Brembo Caliper Rebuild Subaru STi:

Brembo Caliper Rebuild Subaru STi:

A step by step guide to rebuilding a Brembo caliper with rebuild kits. This guide includes separating the calipers as well if you want to go that route:

1.) If you have not yet removed calipers from the car remove them, I cleaned mine prior to starting. You will need to disconnect the brake lines and unbolt them from the hub. Also remove the pads, to remove the pads there are 2 pull pin clips thru a set of long pins. The pins hold the pad and metal bracket in place. Remove the 2 pull pins and slide out the 2 longer pins and everything will fall out. Keep in mind there are small plates on the back sides of the brake pads where the pistons hit the pad, these can be easily lost and are marked with arrows for direction.

2.) You then need to split the calipers apart, to do this I used a impact wrench but if you have some good strength it is possible to break the bolts. Pretty sure the bolts on the front are a 13mm and the rears use a allen wrench style bolt which i believe is a size 6.

Brembo Caliper: Separating the Brembo Calipers and getting ready for the rebuild.
Brembo Caliper: Separating the Brembo Calipers and getting ready for the rebuild.

3.) You will want to pop the pistons out. In order to do this I used, for the rear a inch by 5 inch block of wood, for the front you will need a little thicker of a block. Place the block where the rotor would sit so that the piston doesn’t shoot out and kill someone. (trust me these things will FLY) After doing this i made sure my bolts were very lightly tightened into place, I did this because if you leave the gap the pistons will put force in the way of least resistance which basically means its going to shoot the caliper apart and split it which could cause some pain.

Brembo Caliper: Pistons pushed out of the caliper.
Brembo Caliper: Pistons pushed out of the caliper.

4.)  After splitting the calipers and popping the pistons I removed the rubber seal between the 2 pieces as it is small and could very easily be lost. Don’t remove the o-ring prior to step 3 or step 3 is pretty much impossible.

Brembo Caliper: O-Ring removed.
Brembo Caliper: O-Ring removed.
Brembo Caliper: O-ring location in a brembo caliper.
Brembo Caliper: O-ring location in a brembo caliper.

Brake Pad WRX install 02-05

Brake Pad WRX install 02-05:

This is a basic brake pad removal and install walk through with a Subaru Impreza WRX. Make sure to go slowly to ensure you don’t introduce air into the brake system.

1.)Loosen your lug nuts for the corner you are working on, jack the vehicle up and put it on a jack stand, then remove the wheel.

Brake pad: A Subaru Impreza WRX stock brake caliper.
Brake pad: A Subaru Impreza WRX stock brake caliper.

2.)You now need to dislocate the caliper. There are two 14mm bolts that need to be removed: A lower one, and an upper one. Once removed you can wiggle the caliper back off the rotor, and lay it up on top of the rotor next to the strut. At this point, DO NOT let anyone touch the brake pedal.

3.) At this point you can pull the pads free. I just carefully wedged my finger between the rotor and the pad to lever them free. They locate/remove in a manner perpendicular to the axis of the rotor. There are two of them on each side; remove them both. You will note that the inside pad has a metal ‘clip’ attached to it. The purpose of this is actually to rub against the rotor when the pad material is getting worn low; thus creating the horrid metallic squeal that will remind you your brakes need attention.

4.) Organize the new parts. There are two pads, each with one plastic-coated plate, and one shiny metallic plate, and one metal clip. Subaru also provide some brake grease for you.

5.) Remove the old clips by just dislodging them with your fingers.

6.) Put the new clips located in the position of where the old clips went.