help with trouble codes??

skydivr7673

Registered User
ok, on the way home tonight my check engine light came on. The car seemed to run fine, but there was a loud hissing noise whenever I gave it some gas--almost like I have an exhaust leak or something. when I got home, the car would not idle. It dies if I dont hold the RPMs at about a grand or so. I scanned it and got the following codes:

KOEO--

335 and 522

Continuous stored codes--

157 and 337

335 is the EGR sensor voltage out of range. 522 is for the neutral drive switch, which I am not worried about.

157 is for the mass air flow sensor--below minimum voltage. And 337 is for the EGR valve transducer being above max voltage.

My question in all of this--can a plain old exhaust leak cause this? I thought that the car would not run if the mass air flow sensor was inop, but I was running at about 75 mph when the CEL came on, and it was fully driveable the rest of the way home, so I am not sure what to think here. I do believe that I have an exhaust leak on the drivers side manifold, but I will have to wait til the weekend to get under it and check around. Any thoughts?
 
I thought that the car would not run if the mass air flow sensor was inop

The car will run without a MAF signal. It will just go into closed loop and run off of a defualt MAF table, which is generally pretty rich to be on the safe side. EGR codes pop up all the time, and many times won't effect the way the car actually runs. Sometimes they do though. I think I would concentrate on why that MAF code is coming up first. Have you recently installed a K&N Filter or recharged one? Anything else done recently with the airbox or intake tube that might disturb the MAF?

Thomas
 
I recharged the filter a couple weeks ago, but nothing has been done to it since then. And this is the first time the CEL came on. I will get under the hood later today and see if anything doesnt look right, but I did take a quick look around last night and did not see anything that looked off. I will get back to you with more info after work.
 
Oil from recharging the filter can get on the wires in the MAF and screw with the signal it sends to the eec. Clean the wires and see if that helps. You might need to disconnect the battery to clear the codes.
 
ok, the MAF I am not worried about at this time--I forgot all about a little problem I had after cleaning the filter. I took it for a spin and the CAI tube was not secured well enough to the TB. As I was driving, it came off. The CEL came on and the car began to stumble big-time. I pulled off right away and found the problem, and fixed it. But I never cleared the codes since then....that would explain the code I got.

I am really concerned more about the EGR codes. Could this problem hurt the engine? Or is it just something that affects proper performance, but wont kill it? I noticed that I got two codes for the EGR, and one of them was KOEO, not stored, so that failed the EEC test. That is the first place I am looking.
 
The car seemed to run fine, but there was a loud hissing noise whenever I gave it some gas

This sounds like a vacuum leak to me. Check to see if all the vacuum lines are connected. They can come loose. Also check to see if the seals for the supercharger/intercooler plumbing are good.
 
ok, there is definitely an exhaust leak somewhere near the engine. With the hood up, I started it up. Starts right up, and the exhaust smell is quite heavy under there. Would an exhaust leak, say from the manifold or from under the car, cause the EGR to throw a code like that? The EGR transducer code is for "above maximum voltage", but I do not know how that sensor works, so I dont know if the higher voltage woould correspond with a loss in exhaust pressure that would occur with such a leak.

I just dont want to go throwing parts at it. Any thoughts would be appreciated....thanks guys!
 
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