Code 33

[93StangDech]

Hey guys,
My check engine light is coming on and off very frequently. I put the code reader on it and i am getting only code 33 now.
code 33- EGR not opening - clogged or bad egr, bad EVP/PFF sensor, or sluggish o2.

I have changed both o2 sensors. I took the egr off and cleaned it and checked it over, it appears to operate property, holding suction till i let go of the vaccuum tip.
I put a Air/fuel guage in and it goes rich to lean constantly. Not sure what to make of that.

Could it have something to do with the Baro sensor?

 

[HISSIN50]

Have you confirmed that the EGR position sensor is plugged in? Is the vac line from the EGR solenoid to the EGR intact? Is the solenoid receiving manifold vac? Will the solenoid open when the circuit is closed?
If you apply about 6" of vac to the EGR valve itself, does it open? Does the car start to stumble real bad? It should.

 

[93StangDech]

Hissin50
The EGR valve opens if I apply vac to it. The engine stumbles badly then. The main concern now is the check engine light goes on and off all the time. The EGR solenoid was changed and it gave us code 33 but I put back our old one it goes to code 11. This indicates everything okay but the check engine light acts up. We have replaced the O2 sensors, secondary air solenoids, (engine ran lean all the time) cleaned IAC, cleaned EGR valve, timing set okay, set TPS voltage. Vaccuum at idle is 20 and fuel pressure is set to 43 lbs. Engine idles okay. The air/fuel gauge indicates a lean to rich constant jumping. The BARO sensor was disconnected but made no difference to the idle. Is that normal or should it have done something to the running of the engine? The check engine light still acts up. Any suggestions?

 

[HISSIN50]

If the old EGR solenoid remedies the code 33, what is the code regarding the intermittantly flashing CEL? If it's still a code 33, then the old solenoid really didnt fix the issue.

If the CEL is intermittant and the code is for the EGR, a bad vac line or bad EGR position sensor baseline can be causes.

 

[93StangDech]

I get code 11 with KOEO n KOER when i use my old EGR Solenoid. But i borrowed 2 egr soleniods from a local shop to see if it would change the CEL constant on/off, but it did not fix that, but they both threw code 33. When mine says everything ok and both of the others throw the same code. so i dont know what to make of that, is mine really not operating properly or both of his soleniods bad.

I guess possibly I should start changing vaccuum lines even though i get good vac. I am not sure how to check the egr position sensor to see if it is working properly..maybe i should try n pick one up and just change it and see what happens...

I believe the CEL coming on and off has something to do with the fuel/air ratio. Maybe it cant find a happen medium ratio; jumping from rich to lean too often. not sure.

 

[HISSIN50]

I'm still lost. If you're getting a code 11 only, then whatever EGR you have on the car should be ok. Furthermore, the CEL should not be illuminating at all. If it is, there should be a code stored in the KAM.

The A/F jumping rich to lean is how the stock feedback loop works. It's normal. If it was stuck lean or rich (with hystersis), then something would be wrong.

To check the EGR position sensor baseline, just put a DMM across the sensor's wires KOEO. It should be below .50 volts IIRC. If it's real close to the 'open' threshold, the value can wonder while driving and this can create issues.

Good luck.

 

[93StangDech]

Hissin50,
Thanks for the info. on the rich/lean being normal for it to switch like that. I will check the voltage on the egr pos. sensor tomorrow.

the CEL goes on for 1 min, then off for 5 seconds, then back on for 20 seconds then off for another 5 etc...constantly.
I did not know about this KAM (keep alive mem found within the PCM). I cant find anything on it in my books i have. Is there a way to clear this KAM if there is a code being stored in it thats screwing with the CEL?
Disconnecting the battery doesnt do the trick. CEL still acts up.

 

[HISSIN50]

To clear the KAM, disconnect the battery and let the capacitors in the EEC discharge. Stepping on the brake pedal or turning on the headlights can help this process.

If the CEL is coming on like that, you should have more than a code 11 stored. Be sure the KAM has constant power. If it does, the code should remain till you can retrieve it.

 

[93StangDech]

I checked the EGR position sensor today, it appears fine, voltage checks out as you said.
I pulled the neg. off the battery and turned the lights on for 20-30 minutes to drain the KAM. But im still having that CEL problem yet I am getting code 11 KOEO/KOER. So im at a loss. Thanks for your help though Hissin50. If you can possibly think of anything else to try im all ears.