Hello, everybody!

I bought an 02 Monte a little while back and just started noticing rough shifts, but only when the car is warm and in stop and go traffic. I can drive on the highway for miles and never have a problem, but when I am driving around in the city after a little while, the car seems to jolt into gear. Also, when it is shifting hard, if I get on the highway (or anywhere where I'm accelerating quickly) there is a sulfur smell.

I was reading around and it seems that the pressure control solenoid goes bad pretty commonly in these vehicles, but I was also noticing someone said it could be the catalytic converter? Does anybody have any thoughts on this or things for me to test?

 

Hi Cody & Welcome to the MCF

Below are a few links to check out until one of our expert tech's see's your threads & makes a post Keep checking back.

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7 Symptoms of a Failing Catalytic Converter | DoItYourself.com

 

Sweet, thanks for that video! I will probably get around to testing some of those things this weekend.

I also just realized I forgot to mention that there are no transmission or emissions related DTCs (just a damn wheel speed sensor) reported on any of my scan tools. Also, the shifting seems to be worse at lower RPMs than higher ones when the problem is actually occurring.

 

You're Welcome `Cody,

Check back to see what our expert tech member's post + what other member's that had this problem & how they fixed it...

Good Luck

 

Hi Cody.
The sulfur smell is usually an indication of a bad catalytic converter, but hot/burnt transmission fluid is a bit similar. I don't think a clogged converter will effect the transmission. A failing PCS as well as most other transmission problems will usually trigger a DTC. Higher end scanners can also read real time data like shift time errors, trans. fluid temp and fluid pressure that can be interpreted by humans for further diagnosis.

How many miles are on the transmission?
What color is the transmission fluid? Does it have a "burnt" smell?
When was the last time the transmission fluid and filter were changed?

 

A faulty TPS throttle position sensor can also cause shifting problems. cant hurt to check it out,

 

True, if the the TPS is bad the PCM will put the engine into "High Lock" mode and the transmission won't shift until the RPM's reach about 4,000.

 

~115000.
It's a light red color. I don't think it has any burned smell.
I haven't since I got it this spring. I was planning on taking it somewhere this summer and getting it flushed, but I see some people saying that's not a very good idea with high (ish) miles. What would you recommend?

I get an accurate reading off of the TPS while I'm driving, and it doesn't seem like it's in high lock mode, but I'll do some more research on this.

From my small amount of research, it doesn't look like cats are too expensive, so that might be the first place I start, since it seems like it needs it anyway.

 

The decision to flush or just drain and refill depends on the practice of the previous owner. If it was flushed at 80K you can flush again. If not flushing can cause problems by dislodging metal trapped metal fillings and cause more damage than no service at all. If in doubt, just drain the fluid and refill with Dextron VI (Synthetic) and replace the filter. light red (pinkish)color and lack of a burnt smell is good. Save and re-use the pan gasket if you feel the stiffness of the metal core. The OEM ones came that way and are re-usable, way better than the all rubber aftermarket ones that sometimes come with new filters. Sometimes a service is all it takes, might just be a clogged filter. Worth trying before repairs anyway, although 115K is about the mileage when some PCS's fail.
As for the cat., the mileage is still pretty young for needing replacement, and it should be throwing a P0420 code for that. Their usually good for 150K or so.
Good luck and keep us posted.

 

[QUOTE=codyswanson4;689664]Hello, everybody!

I bought an 02 Monte a little while back and just started noticing rough shifts, but only when the car is warm and in stop and go traffic. I can drive on the highway for miles and never have a problem, but when I am driving around in the city after a little while, the car seems to jolt into gear. Also, when it is shifting hard, if I get on the highway (or anywhere where I'm accelerating quickly).

I have the exact same issue with my 06 you explained my problem to a T. If you figure anything out or fix the problem let me know please