5.0stanger

Got a code 66 (MAF voltage too low) and a code 33 (EGR not opening)

As far as code 33, I don't have EGR, so is that the code that should be there to eliminate it properly with a simulator?

Code 66, is my MAF bad? My car was cold doing this test if that matters...if not, what should I look at to get the proper voltage?

Thanks

Joel5.0

Code 33 = you have an EGR delete courtesy of the EEC-IV system, the simulator will cause that same code to be logged, and is not a code that will cause the CEL to turn on. No problem there.

Code 66.....you might want to try to run a KOER self-test and check if it shows up.....if it doesn't....clear codes (disconnect battery) and retest it (KOEO) to confirm it's gone....if not, you might want to check it following the tests described below......

5.0stanger

Ok yeah, it was running KOEO, I will try the KOER. If I do see it again, and I run the other tests, the second one, is that signal wire to the return wire, then the signal to the ground(so 2 tests?) and that is on the MAF or harness?

Joel5.0

First 2 tests from the diagram are on the harness, MAF disconnected...third one is MAF connected, probing MAF SIG wire voltage output ER =(Engine Running).

5.0stanger

got ya, thanks

Blckstng93

I had stalling in reverse from a cold start. Had it scanned and found a 66. Replaced my MAF and no more stalling.

Try cleaning your MAF and see if that helps.

5.0stanger

Okay, ran the KOER test, still got the code 66.

So I did the 3 other tests

first one, I had over 10.5 volts

second one, don't know if I was doing it right. I was testing between maf sig and maf return forohms and then maf sig and ground for ohms on the harness,MAF unplugged key on. I wans't getting any ohms...not sure of the problem, but I check all the wires running the the MAF from the computer and the all were good.

third one, engine running at 800rpm idle I was getting 1.8 to 2.2 volts. It was jumping around a bit and my idle was surging.

Also, when I ran my KOER test I got code 98. What does that one mean?

5.0stanger

I just cleaned the MAF about a 6 weeks ago.

Joel5.0

Code 98 KOER means that the KOER is inaccessible until code 66 (hard failure) is fixed....since code 66 = MAF signal below minimum test voltage of .4vdc (O,M,R) and you have "1.8 to 2.2 volts engine idling @800 rpms"....need to make sure that voltage is the same when measured at pin's 50 wire in the ECM connector.....if it's lower, that wire has an open......if it's the same, looks like the ECM is kaput. If the voltage input to the ECM is above .4vdc, and the ECM logs it's below .4vdc (code 66)....that EFI brain is bad.

I would monitor the MAF voltage at the ECM connector wire while you try to run a KOER....if the voltage is above .4vdc. and code 66 continues to show..........you know the rest.

5.0stanger

I am sure the are no problems with the wires, I just did the MAF conversion and the wires are all new. I will have to look, and give napa a call (I got it from them....) Thanks