MISFIRE ON ALL CYLINDERS AND EGR TEMPSENSOR HIGH CODE ...Your thoughts please...

[SRivers33]

Hey everyone, first off, I have in fact read Donkeys post about Misfires. I just wanted to whittle this down a little more. So here are the details and then my thoughts...


2002 WRX on E85 and a ECU tuned for WOT. 18PSI FP Turbo. Hallman Pro Manual Boost controller.

1.The car hasnt felt or sounded like its misfiring...Its only felt like a misfire today for about 15 seconds...then it smoothed out and was back to fine.

THE PROBLEM

2.So three days ago it threw a P0302 code for a misfiring no. 2 Cyl.
It is tuned for WOT and it had bogged down a bit when i shifted too low one day so i figured that was the reason and deleted the code.

3.Drove it 120+ miles without any issue and then last night it threw another code.....so i pulled the battery cable and replaced it 15 mins later to clear the code figuring it must be the same one. (My diag tool wasnt with me).

4.Today by the time i get to work the Check Engine light is on again. I check the code and find that now its throwing these codes...

P0301 Cyl 1 Misfire
P0302 Cyl 2 Misfire
P0303 Cyl 3 Misfire
P0304 Cyl 4 Misfire
P0546 EGR Tempsensor Circuit High



MY THOUGHTS

To address the Misfires first....

1. Ignition_______The previous owner and i are still friends...he thinks its an ignition problem...(My problem with that is 1.It would be strange for all the coil packs,spark plugs, plug wires, etc to all go out at once. No?)

2. MAF________If it was the MAF wouldnt it throw that specific code? Also i have a A/F gauge that reads anywhere from 15-17 during idle....this seems normal to me.

3. FUEL PRESSURE REGULATOR______This is an aftermarket version that has been on the car for over a year...

4. Vacuum Leak____Honestly no idea if this is it or not but one friend of mine says you would be able to hear it and....i cant hear anything different so....not sure

5. I have considered a compression test but dont see how i would lose enough in all 4 simultaneously to create this problem...

6. I have wondered if pulling the battery would have reset the ECU possibly and created more problems for myself since the tune that the timing is advanced for would no longer be there....??????


NOW FOR THE EGR CODE

Only thing i could think is its burned out.....i have a high flow cat.....





Is it possible that this was actually the first problem and it caused the misfires?




Any info would be greatly appreciated.

[Anub1s]

First off, is the AFR gauge hooked to a wideband O2? If not, it's completely useless. If so, your idle AFR should be trying to stay around 14.7, if the car is never able to maintain an AFR around 14.7 there is something wrong mechanically. An AFR of 17 at idle is indicative of a leak after the MAF housing.

A leak like that which throws off AFR's can easily cause a lean condition would could cause the misfires AND potentially damage the engine. I would not drive that car until you get it all sorted out.

[SRivers33]

Thanks for the quick reply. That bad huh? Didn't realize that. So what should be my next move? Start looking for vacuum leaks or.....?

Also not sure where its hooked up. Previous owner did it. I'll find out tomorrow

[Anub1s]

That's what I would do. Check for cracks in all of the intake and charge piping and make sure that everything is seated properly. Check your vacuum lines for cracks as well.

[SRivers33]

awesome man thanks. Am I correct in Thinking that doing a compression test would be premature at this juncture?

[Donkey]

No EGR on the WRX. EGT.

[SRivers33]

Thanks D. You did read the first sentence of this post right? My question is my car specific...that's why I started a thread...am i missing something?

[Mikie13]

Pulling the battery would only reset the ecu, not remove a map on it for the particular mods. It would have to "relearn" some of the timing when driving and so on, but it wouldn't remove a tune.

[Donkey]

My question is my car specific...that's why I started a thread...am i missing something?

Yes. That code is for the factory Exhaust Gas Temp sensor. In my 20+ years of modding cars I have yet to see some one add an EGR valve as a performance enhancer. Most people take them off and there is not one to take off a WRX as it did not come with one. So that being said either the EGT sensor is borked/gone or you still have the factory up-pipe cat and there is a problem.
1. There are no plug wires on 02 WRX. Coil on plug. If your crank sensor has a problem then it could cause a misfire on all cylinders. So can jumped timing.
2. Clean the MAF. There is no code for a dirty MAF. And for the most part the MAF will continue to function but just be inaccurate. Idle AFR should be between 14.2:1-15:1 AFR
3.Then test the fuel pressure.
4. Listening for a vacuum leak is the caveman way of doing it. Either use a smoke machine or actually go over the car and visually check all the lines. Could also be a post MAF/preturbo air leak or even a gross boost leak.


List all of the cars mods........

[SRivers33]

Awesome stuff Donkey. That's what I was hoping for when I posted this. Someone who knows far more than I do. Thank you man. After work today I'm taking it to my friends shop to do all the things you mentioned. Also found a new symptom.

Drove it to a diagnostic shop yesterday. On the way there I was cruising at 70 in 5th. Went to overtake a truck and got what felt like a boost spike and the feeling as if I had depressed the clutch. It only happens in 5 from 3800rpm to 4300rpm from what I can tell. turn the boost down and see what happens Is all i can think to do.

Getting a comprehinsive list of all the mods but the ones i know off the top of my head are

Fp hta68 turbo
Hallman boost controller
Aftermarket fuel pressure regulator
899lb injectors
Walbro 255lph fuel pump
Front mounted spt intercooler
Custom up pipe, downpipe, and 3 inch exhaust from the turbo back

[Mikie13]

Boost cut occurring as well? Is this thing tuned properly???

[SRivers33]

Boost Cut??? That sounds like what it felt like. It was so weird. One guy at my local shop said it sounded like the clutch my be going but it only happens when going from cruising to WOT in 5th. If i am at WOT from 4th into 5th then it just keeps pulling.....

The Comprehensive list of parts.

890cc Injectors
Walbro 255 Fuel Pump
Aftermarket (Brand unknown) Fuel Pressure regulator at 40-45 psi
Short Ram Intake w/K&N
OBX Headers and bell mouth downpipe
Unknown Brand Uppipe
SPT 3'' Exhaust w/High Flow Cat
TGV Deletes
Grimmspeed Phenelic Spacers
FP 68HTA Turbo
HKS SSQV BOV
Hallman Pro Boost Controller
Front Mounted SPT Vishnu Intercooler
Perrin 22mm Front Sway Bar
Open Source Tuned by Harvey at The Boost Creep Ltd - Dyno Tuning and Automotive Services in Longmont Colorado



Today i replaced the plugs, tried to tighten the crank pulley (Didnt feel much move), and cleaned the MAF.
Didnt throw any codes on the 5 mile drive home from the shop.


Tommorow if i have time i'll be checking the fuel pressure and possibly changing the regulator.

Whats this Boost cut??? Off to do a google search. thanks guys. Really appreciate the community helping me out here.

[SRivers33]

Read up on Boost cut and Fuel cut....cant find a decent description of the feeling of boost cut. Tottttttallly feels like fuel cut though....

any reason it would only happen from cruising to wot when it works fine from 4th with WOT???

[Donkey]

On the way there I was cruising at 70 in 5th. Went to overtake a truck and got what felt like a boost spike and the feeling as if I had depressed the clutch.

If the rpms' shot up then back down without the car really going anywhere then it is your clutch. "Custom" up and downpipe? Not sure why it would be "custom" considering you are running a bolt on turbo. Do you mean "aftermarket"? If you have an aftermarket up-pipe I am assuming the previous owner removed the EGT probe. What engine management is on the car? No offense but buying a highly modded car when you know little about it is generally a bad idea. You end up buying someone else headache. With out hard actual data to look at it can be any number of things. Thats why datalogging has become so popular. Makes diagnosing cars remotely much easier. The boost cut is just like the rpm limiter.

[SRivers33]

Don't know about the engine management. Your right though its troublesome to say the least in this case. I'm glad I'm still friends with the previous owner as he has been a big help so far. No codes thrown today in 30+ miles of driving.
Haven't had it on the freeway to try 5th.

Aftermarket pipes is correct btw.