Chrysler Repair: Input / Output sensors, autoparts store, speed sensors

Question
QUESTION: Our mechanic said with miles and age of vehicle that it is possible the input / output sensors on tran are bad. I will describe issue and you can give me your opinion.

We were driving and all seemed to be well. Then engine began to act up. Never overheated or anything, just wouldn't shift properly, RPMs would go to 3500 - 4000 before it would shift. Then worked OK for a short time then the same. Very hard to accelerate. We had our grandson so headed to his house to drop him off. When we got there and parked(about 20+ minutes) the car was smelling like burning rubber and a light colored smoke began to come out of the wheel wells (front) and out from under hood.

I let it cool and checked fluids. Tran was clear and pink and good level and oil was good level and OK too. After cooled drove home (1 mile). Drove OK, but never exceeded 35 MPH and it has been sitting since. Moved it in driveway OK. Took off tires to see if brake issue. No squeaking or rubbing sounds. Pads are low, but nothing seems "bad". Saw a bar hanging loose in there on driver's side. Possibly a sway bar? Not sure what it is or what it does, but should probably replace it.

Does the issue fit with bad sensors? Are they expensive and can I replace them myself?

Thanks,
Tim

ANSWER: Hi Tim,
I don't think it is the speed sensors, although the improper shifting can be caused by one or the other of those. But the smoking, and the detached bar are indicative of some other cause which should be resolved before thinking about speed sensors which are just part of the electronic control function of the transaxle. There are also on-board diagnostics which can help for either engine or trans malfunctions and which you can get done (code readout) for free at an nationwide autoparts store such as Autozone.
So see what the deal is with the hanging part, get the fault code numbers (4-digit) and tell me the year/make/model/body style/engine of the vehicle when you write back.
Roland
PS Please 'rate' my answer, and where you see the question about a nomination of me to be 'volunteer of the month' consider a 'yes' response. Thank you

---------- FOLLOW-UP ----------

QUESTION: I have been told that the detached bar is a "sway bar". What exactly does it do? I will replace that and get codes checked.

Thanks,
Tim

ANSWER: Hi Tim,
It is part of the chassis suspension that provides a firm but flexible attachment between the lower control arms on the two sides of the suspension. It helps resist leaning when going around a corner and thus improves the control and comfort. It is held in place by rubber-bushing brackets that are attached by bolts to the suspension. It may be that one of those came loose, and they are a stardard replacement part.
Roland
PS Don't forget to tell me the specifics of the vehicle. Also, if you could 'rate' either this of the previous answer I would be most appreciative.

---------- FOLLOW-UP ----------

QUESTION: OK Roland,

Here it is. The only code that shows up is "P0403 Exhaust Gas Recirculation Control Circuit"...More specifically "EGR "A" Control Circuit/Open"

I checked it then cleared it. Drove a short distance and light went back on and code was same again. I wouldn't think this should cause the issues I was having though.

Also, for some reason after I repaired the sway bar all the issues have disappeared. This kind of concerns me, because it appears everything except this code is OK. We are supposed to be going on a 1200 mile trip this next week and I would like to be sure.

I took it for a drive last night after fixing the sway bar, ran it today with and without the A/C on and my wife just took it to a town, roughly 25 miles away (50 round trip) and no issues.

The engine is 6 cyl 3.3L, car has 235,000 miles on it and has to this point given us little trouble beyond normal maintenance.

Any further thoughts?

Answer
Hi Tim,
If you checked the egr circuit for electrical continuity and found that to be alright, then I would go back to the egr valve itself and check to make sure that the valve stem is not gummed up such that it is either not opening or not closing tightly. Use the tip of a screwdriver in the slot of the valve stem to move that back and forth, against spring-action in one direction that attempts to close it. If it is sticky or doesn't close to a dead stop by the spring-action then spray some WD-40 on the stem where it enters the body and work the stem some more to free up the action. See if that solves the engine performance issues you had earlier and also keeps the check engine light/0403 code from reappearing.
If you didn't check the wires to the egr let me know the year/make/model of the vehicle and I can tell you how to trace them. At 235K though I would believe the egr valve is pretty gummy.
Roland