Our problems began with surging while going up slight grades.
One suggestion was the transmission was not sure what gear it wanted to be in. This was the beginning of our problems.
Mileage: 212K.......car's probably toast, but we continued.....
Local mechanic said it was a transmission issue.....proprietary information.
Dealer replaced the Fuel Injection Module. Got the car back, then it surged and overheated.
Dealer said it was the transmission, specifically torque converter.
Got the car back after new tranny installed and it surges, overheats and stalls. Dealer said now it was crank sensor (probably the original issue all along). Dealer wanted $650 to replace crank sensor. Forget that, took it to a local mechanic who replaced it for $150. Put the car on a dynometer, twice, all tests passed.
Car is back the original issue, surges while going up sight grades.....
Anyone have any other ideas? Gas is good.
I am hearing something about a knock sensor?? Vacuum leaks?
Just need the car to run a few more years of light use......thanks!

 

2 thoughts come to mind for me.

A fuel delivery problem of some sort. Maybe the pump is failing, filter is being restrictive?

Second thought, clogging catalytic converter. Known issue on the 2000/2001 years

 

+1 to what Mike said.

Welcome to the forum

 

Here is a link to common problems with our cars, it may help you out.

https://montecarloforum.com/forum/fw...lutions-30154/

Have you changed your tranny fluid? Our trannies are notorious for failure, and they do sell a sonnex cure kit for them, but if you change the fluid don't do a flush, just replace the fluid and filter as flushing it may make the problem worse.

Also one trick to check if you cat is plugged is to start the car and let it run and take a look underneath the car and see if it is glowing red, this is usually a bad sign, it may still be bad if it's not glowing but it's a quick cheap test for you to try out

 

He said he changed the whole trans, so I think it's safe to say new fluids