[Alchemist]

My son told me his 91LX 5.0L flashed a CEL for a brief second, maybe twice this week. We read the codes with key on/engine off: 32 and 95

With engine running we got two different ones: 12 and 21 (I believe the engine had cooled down a couple hours - probably not anything to worry about?)

What should I look for? The 32 appears to be an EGR fault: EGR Valve Position/Pressure Feedback EGR Voltage Below Closed Voltage. 0.24 volts (O,CM,R). Would this be the EGR vacuum regulator or the position sensor? The code 95 is weird - something about a fuel pump circuit open.

 

[indy2000]

32 is most likely worn out position sensor, you could do a battery of tests or replace both the egr and evp
95 is a montitor, indicating a voltage on the fuel pump circuit is either high or low, when it shouldn't be, possible wiring or pump issue
12 is not good, and I would guess this has an aftermarket Throttle body, and air flow is incorrect to create a stable controlled idle
21 may be you checked not at operating temp

recheck when at operating temp

 

[Alchemist]

Thank you. I suspected the position sensor for 32. Do any folks simply bypass the EGR? My state doesn't have emission testing so if it doesn't hurt performance would just as well eliminate.

For 12, no I don't have an aftermarket throttle body or intake.

 

[boostup89]

Thank you. I suspected the position sensor for 32. Do any folks simply bypass the EGR? My state doesn't have emission testing so if it doesn't hurt performance would just as well eliminate.

For 12, no I don't have an aftermarket throttle body or intake.

It would be counter productive to eliminate the egr in hopes of a performance gain.

 

[indy2000]

Thank you. I suspected the position sensor for 32. Do any folks simply bypass the EGR? My state doesn't have emission testing so if it doesn't hurt performance would just as well eliminate.

For 12, no I don't have an aftermarket throttle body or intake.

working egr is good to have

12..........back probe all three wires with key in run

report what you get

 

[Alchemist]

By backprobing all three wires, do you mean the ILC wires?

 

[indy2000]

TPS, back probe those 3 wires

 

[Alchemist]

Replaced the EGR position sensor a couple weeks ago, along with the battery and alternator (probably cleared some codes). Now, I don't get any CEL flicker while driving. I did check codes though today and now I'm getting a 31, which I hadn't gotten previously. The 31 was only with KOEO. With KOER, no codes at all.

What might be the remaining issue with code 31, with KOEO?

 

[indy2000]

if you do not replace the EGR and EVP as a unit you will get that

the EGR is worn in the location where the EVP senses.

You still did NOT answer the TPS voltage question, just keep replacing parts.,

Also, the CEL illumination is not specific in timing, it can happen when it decides and is usually random.

 

[Alchemist]

Sorry Indy,
I have plans to test the TSP. But just making sure you know that now I only get code 31. All others are gone.