Transmission problems, gas cap, and rotten egg smells?


Asked by Jan 16, 2008 at 02:59 PM about the 2001 Pontiac Grand Prix

Question type: Maintenance & Repair

Sometimes after driving for some time, I park my car and when I get out it smells like rotten eggs.  I have had more problems with this car and I am getting ready the have the transmission worked on or replaced for the 4th time.  THe first 2 times it was under warrenty and they would keep my care for months, the last time it cost about $800.00.  ALso the service engine light keeps comeing on and they claims that the gas cap is not put on correctly.  I know how to put the cap on, it not that hard.  
Any help would be greatly appreciated......

3 Answers


rotten egg smell, sounds like a cat' converter. if it was/is plugged it could cause some back pressure and throw off your O2 sensor, you should have this checked. as regards to the gas cap, yes if it is on wrong or the seal is worn it will trigger a "check engine" light, it may need replacement. as for the tranny, what is the milage on the car and each rebuild? If my tranny went out 4 times I would get the whole car checked for something else being wrong, (something bent, bad rebuild --> this will only count for one or two rebuilds, after that there is something else wrong) How is the car driven? (city - stop and go or racing) do you come to a complete stop before changing direction? (this is a very common issue for blown trannys). But if it is the tranny have a new mech to have a look at the whole car to see if something bigger is causing these issues. it never hurts to get a second opinion. I hope this helps, best of luck.

1 people found this helpful.

You might feel that the tranny is going because a clogged cat will do this. The trans bogs down from back pressure created for the exhaust gas not being able to flow correctly. The rotten egg smell is from the catalytic converter not functioning correctly. There are many reasons a cat can become clogged, but the point is to have your cat looked at first. Having a bad cat will also trigger your check engine light.

1 people found this helpful.

most likely the cat converter, but if you wanna go the cheap route first, have a professional fuel injection cleaning done. It costs around 20 dollars, and can also cause the rotten egg smell

1 people found this helpful.

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