Issues with my P5

[Nyshadow]

So i have been having some issues lately with my P5. Idle has been real choppy, like it wants to cut off. So i did a little research on the forum and figured it was time for a tune up. So i replaced the Spark Plugs, wires, and Coil packs. Replaced the air filter and gave it a oil change. She ran a lot better after the tune up but shortly after i noticed the idle was real choppy again. CEL came on, pulled the code and it was a EGR code. I took the EGR valve off and it was in pretty rough shape, pretty rusted. So i replaced it and the gasket. EGR code went away and car ran better. Car sat for a little while in the garage, at the time i had another car and a motorcycle and when the weather was nice i would ride my bike. So fast forward to present. I drove the car to work one night a couple of weeks ago and i noticed idle was real choppy again, i'm like WTF. CEL came on once again. P0421 (Warm Up Catalyst efficiency Below Threshold) So I'm thinking, great i need a cat. So i was thinking about doing a aftermarket header, but wasn't sure. So i did the de-fouler trick. Cleared the code and drove the car for a few days, then CEL came on again. P0455(EVAP System Leak), P0660(Intake Tuning Valve Control Circuit) and P0131(02 circuit low voltage bank one sensor 1). Cleared the Codes, Drove the car for a few days. CEL came back on. This time it's P0131 again and P0660. So i park the car in the garage and take my other car. P5 sits for about two weeks. I started it up tonight and no CEL, but idle is choppy. So i'm thinking there is still a issue. I'm going to drive it and see what Codes come back. (shrug)

 

[whatusername]

replace the top o2 sensor and remove the non fouler. u only do that after adding a header when removing the pre cat

 

[Nyshadow]

So you can't do the non Fouler on a stock setup? Also i already changed the top 02 sensor.

 

[Nyshadow]

So i switched the non-fouler to the second sensor and left to car idling in the garage. CEL came back on, P0300 random misfire. (scratch)
Plugs wires and coil packs were replaced.

 

[kosteniuks17]

Sounds like you might have a intake leak somewhere to me. Make sure you dont have a small crack or tear in you intake and make sure its secure to the throttle body. Also just check the battery connections too make sure there tight.

 

[pcb]

So you can't do the non Fouler on a stock setup? Also i already changed the top 02 sensor.

I'm pretty sure you can. A stock set up with the dead pre cat is essentially a header, the non fouler should work fine.

 

[pcb]

So i switched the non-fouler to the second sensor

The non fouler only ever goes on the second o2 sensor.

You may have a fuel issue. ( maybe a clogged fuel filter, failing fuel pump, fuel pressure regulator, dirty or bad injectors, ect.)

You should do a fuel pressure test.

It could be causing all your problems, including the ECU giving out random codes (it could be confused).

 

[pcb]

Sounds like you might have a intake leak somewhere to me.

That makes sense,... a leak can cause a misfire and stumble.

 

[Nyshadow]

Sounds like you might have a intake leak somewhere to me. Make sure you dont have a small crack or tear in you intake and make sure its secure to the throttle body. Also just check the battery connections too make sure there tight.

I replaced the Intake hose. I'm going to check the battery connections as well.

 

[Nyshadow]

The non fouler only ever goes on the second o2 sensor.

You may have a fuel issue. ( maybe a clogged fuel filter, failing fuel pump, fuel pressure regulator, dirty or bad injectors, ect.)

You should do a fuel pressure test.

It could be causing all your problems, including the ECU giving out random codes (it could be confused).

Ok I'll do a fuel pressure test.

 

[Nyshadow]

Sounds like you might have a intake leak somewhere to me. Make sure you dont have a small crack or tear in you intake and make sure its secure to the throttle body. Also just check the battery connections too make sure there tight.

Well my friend Chuck figured out what was wrong with my P5, there was a Vacuum hose on the intake that wasn't connected. Just was dangling there, but it was wrapped around the other hoses so i didn't see it. I connected that puppy and the idle was normal again. Car runs like a million bucks now. I'm pretty sure i either knocked it off or i disconnected it when i changed the EGR valve. I want to say you guys on this website are awesome. My P5 is back in action.