Code 32 Root Cause

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Oct 31, 2012 | 04:19 PM

Fender Engineer

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Junior Member

Joined: Oct 2009

Posts: 3

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From: Corona CA

Car: 91 Camaro Convertible RS

Engine: Currently 5.0L

Transmission: 700R4

Axle/Gears: Borg Warner 3.27

Code 32 Root Cause

I am certain that I have identified the root cause of the code 32 nightmare that plagues my, and many others camaros. First I need to let you know what car I have, so there is no confusion. I have a 1991 RS convertible with a stock 5.0L and the tbi setup. The only engine/driveline mods my car has is a rebuilt borg warner rear axle with 3.27 gears and a stainless magna flow catback exhaust. So…as many of you know, code 32 can be a real bitch. It seems to come and go and no one on here has identified a concrete answer on here yet. But I am 99.99% sure that I have identified it. Code 32 means you have an EGR fault. So, like any engineer, that’s actually worth his salary, I decided to get my hands dirty and figure this out. Upon inspection I noticed that the majority of my vacuum hoses connected to the egr system were rotten, so I replaced them all. Drove the car around…didn’t really notice a difference and still got the dreaded service engine soon light. Then I decided to buy a new egr, egr solenoid, and map sensor. Replaced them all, drove around with no difference and still got the SES light. Read every post on here and no one seemed to ever say why exactly this was happening. I actually figured out how to cause the error code to come on. I can cause the code to fire if I am in overdrive and have the car in cruise control above 50 mph. Without fail the SES light will come on with the code 32 error. If I do the same test, with the car in Drive, the SES light never comes on. I was really scratching my head at this point. I read some good posts about a guy who stuffed some rags in one side of his dual exhaust to increase back pressure and he said the error went away. So, I decided to dig a little deeper. I connected a vacuum gauge to the egr valve to make sure that it was working properly. I drove the car around in drive at 50 mph with the cruise control on, the vacuum stayed around 13-14 in of Hg, which is good. The service engine soon light never came on. I repeated the test in Overdrive, 50 mph, cruise control on and noticed something really strange. The vacuum gauge would read 13-14in of Hg for a about 15 seconds, then it would sompletely shut off. It would go back to 13in of Hg for a few seconds and then die off, basically it would keep repeating this if I was in overdrive. Oh yeah…the SES light came on in overdrive too. So, here is my theory based on real testing, not an opinion: The free flowing exhaust is confusing the ECM. When I am in drive and have a nice audible back pressure rumble the vac gauge never falters and SES light never come on either. If I am in OD, the engine isn’t working as hard, there is less back pressure, the vac gauge jumps around, and the SES light comes on. So, I believe the exhaust is actually the root cause of the error and I will now ignore the SES light when I’m cruising in OD. Do you think anyone can make a new chip that would solve this error?