[russ93spirit]

Daughter's Lebaron with 2.5L TBI. She noticed engine bogging down and hesitating when pulling away from a stop today. I drove the car and also noticed some hesitation at crusing speed around 40 mph, but no bogging as severe as what she described.

Pulled codes, and I see a 21 and a 32, for Oxygen sensor and EGR valve. I understand these symptoms match up to the O2 sensor possibility, but could the two codes be related? Also, she has not been driving car long enough for me to get a good idea as to her fuel mileage, and I know I need to check that.

If I am not mistaken, the egr code would result in rough idling on occasion, which also appears to be the case here.

 

[chuzz]

I don't know about the codes, Russ, but it's easy enough to pull the EGR and check it for carbon build up. If it's not that, and the valve works okay when you put a vacuum on it, then it could be that pesky transducer.

 

[russ93spirit]

thanks, Chuzz...that's true. I doubt carbon buildup though, as the car hasn't been on the road that long. It was a used egr I put on the car when I assembled everything, but I would have noticed carbon buildup. Will check it and the transducer asap.

 

[Doug D]

Russ - to check the EGR just disconnect the vacum hose - if the idle evens out, then the EGR needs replacement. I don't think you can just replace the transducer. It's only sold as a complete unit. As for the O2 sensor - I've had good luck with Eglin sensors (from NAPA). You might need a special socket with the slit up the side for the wiring - it does make it slightly easier. Soak the threads with WD40 or something similar. You may need a breaker bar.

 

[russ93spirit]

Thanks, Doug...I have the correct socket from work in the past. I guess I'll go ahead and swap the sensor and not second guess the code.

 

[Bob Lincoln]

Inspect the vacuum transducer on the EGR. Consider the possibility that a plugged catcon can back up hot exhaust and cause the EGR to fail/melt. Under those conditions, the O2 sensor could give a 'lazy' code 21.

I'd fix the EGR first and see if the O2 is then OK.

 

[russ93spirit]

makes sense, Bob L. but I grabbed an O2 sensor on the way home before I read this. Put it in the car just a while ago. A quick look at the transducer last night didn't reveal anything obvious, but will look hard at the egr and transducer tomorrow. (Also had to install a new caliper, flare a steel brake lline, bleed brakes, etc on my other Lebaron tonight.)

 

[ImperialCrown]

The transducer housing unclips around the circumference for disassembly and inspection. There really is nothing inside that can be serviced. I have found some with rusty, sooty water inside from the exhaust condensate. An EGR transducer and valve are serviced together for replacement. The transducer is likely the failed part in many cases.
Sometimes removing the vacuum hose as a test isn't always valid as I have seen the pintle at the end of the valve stem missing or burned off. And the vacuum hose test makes no difference.

 

[chuzz]

Back when I had my 94 Spirit, I had to replace the entire thing, Russ. Even though the EGR valve tested good, the transducer was at fault. IIRC, the unit was around sixty bucks at Advance.

 

[Bob Lincoln]

To test proper EGR operation on these engines:

Warm it up and have someone rev the engine to about 2000 RPM for a second. The EGR stem should move and then return to the closed position. If it does not, it is either stuck, or part of its control has failed. If you do this test with a cold engine, it should not move - the EGR will only activate on a warm engine.

Second test: On a running warm or cold engine, grab the EGR stem with needlenose pliers and lift it. The engine should stumble and/or stall. If it doesn't, the EGR passage is clogged.