Help going crazy!

**cmccarty22** · 10-15-2013

All highway miles. I need to get this car inspected any other suggestions.

thanks

chris

**Scottydoggs** · 10-15-2013

take more short trips, it needs so many drive cycles to get ready.

**cmccarty22** · 10-15-2013

Ok thanks I will drive it all over the next couple of days I hope this will work.

thanks

**cmccarty22** · 11-13-2013

Thanks to all that help got the car inspected! Now the right rear window is not working(lol) I give up
thanks

Chris

**dsmuts** · 11-13-2013

window regulator. Easy fix.

**cmccarty22** · 11-17-2013

Yea the wire fell off from the kids slamming the door to hard.

A new problem came up today the fuel gauge is going up and down. The fuel gauge goes from full to empty.

thanks

**02NavyBlue** · 11-17-2013

http://www.ebay.com/itm/Chevy-Buick-...f19369&vxp=mtr

I had the same issue on our impala, would go from full to empty randomly. The teeth wear out on the variable resistor, this kit fixes it. I did it for my first time and it took me like a half hour.

**tech3627** · 11-17-2013

Putting a spark plug non fouler on the rear O2 sensor is not fixing the problem, it is tricking the computer by giving it false readings. There are test that can be done with a scan tool to find what the problem really is. It is possible the front or rear O2 sensor is not reading correctly causing false reading to the computer. I don't know if the dealer put a factory converter or an aftermarket one on, but there is a huge difference in them. That is why there is such a big price difference with them. A catalytic converter works because it has precious metals inside it. The aftermarket ones do not have as much of those precious metal in them so they do not work as well. Some of the aftermarket ones will not work on OBDII vehicles.

If it has only been a couple of hundred miles since the dealer diagnosed it I would take it back and talk to the service manager. I worked at 2 different GM dealers for a total of 9 years I know how they operate. It makes a huge difference which tech gets the job. There are good and bad technicians in just about every shop out there including dealerships. The service manager should get involved if they have had 2 attempts and the problem is not fixed. I have never seen a computer be the cause of a P0420 code. I have seen software updates for a P0420. You can go to this website and see what the current software is and any updates for your vehicle by entering the VIN. https://tis2web.service.gm.com/tis2web. There are no TSBs for any issues with a P0420 code on your car, but that does not mean there is not a software update.

If the dealer still says it is the computer I would request that they call GM's TAC (Technical Assistance Hotline) to see if they agree with the dealers diagnosis. I would be VERY surprised if the PCM is the cause of this failure. I would guess at least one of the O2 sensors was defective

**cmccarty22** · 11-18-2013

The car is running fine now after th spark plug trick. The only thing I need help with is the fuel gauge is going from full to empty

thanks

**02NavyBlue** · 11-18-2013

Originally Posted by cmccarty22

The car is running fine now after th spark plug trick. The only thing I need help with is the fuel gauge is going from full to empty

thanks

Right here

Originally Posted by 02NavyBlue

http://www.ebay.com/itm/Chevy-Buick-...f19369&vxp=mtr

I had the same issue on our impala, would go from full to empty randomly. The teeth wear out on the variable resistor, this kit fixes it. I did it for my first time and it took me like a half hour.

**cmccarty22** · 11-19-2013

Thanks I just order the part I hope the weather gets a little warmer so I can get this done

**02NavyBlue** · 11-19-2013

Yeah, it's pretty easy really. Once you remove the fuel pump assembly, you can take it into a garage or somewhere out of the cold and replace the sender there. I wouldn't take it in the house since there will be gas still in it(if you don't want your house to smell), I worked on it in a drain pan. There's a video online that makes the job a breeze. He just replaces the arm, just do the whole thing. Also I re-used the stock gasket since I've heard of fitment issues with the new.

Part 1: http://www.youtube.com/watch?v=-7cY_IPCVfI
Part 2: http://www.youtube.com/watch?v=FST1whbcOk8
Part 3: http://www.youtube.com/watch?v=9N16YmV9xcw

**cmccarty22** · 12-19-2013

Originally Posted by tech3627

Putting a spark plug non fouler on the rear O2 sensor is not fixing the problem, it is tricking the computer by giving it false readings. There are test that can be done with a scan tool to find what the problem really is. It is possible the front or rear O2 sensor is not reading correctly causing false reading to the computer. I don't know if the dealer put a factory converter or an aftermarket one on, but there is a huge difference in them. That is why there is such a big price difference with them. A catalytic converter works because it has precious metals inside it. The aftermarket ones do not have as much of those precious metal in them so they do not work as well. Some of the aftermarket ones will not work on OBDII vehicles.

If it has only been a couple of hundred miles since the dealer diagnosed it I would take it back and talk to the service manager. I worked at 2 different GM dealers for a total of 9 years I know how they operate. It makes a huge difference which tech gets the job. There are good and bad technicians in just about every shop out there including dealerships. The service manager should get involved if they have had 2 attempts and the problem is not fixed. I have never seen a computer be the cause of a P0420 code. I have seen software updates for a P0420. You can go to this website and see what the current software is and any updates for your vehicle by entering the VIN. https://tis2web.service.gm.com/tis2web. There are no TSBs for any issues with a P0420 code on your car, but that does not mean there is not a software update.

If the dealer still says it is the computer I would request that they call GM's TAC (Technical Assistance Hotline) to see if they agree with the dealers diagnosis. I would be VERY surprised if the PCM is the cause of this failure. I would guess at least one of the O2 sensors was defective

The dealer has replaced all the O2 sensors and 2 catalytic converters one at my cost and one at their cost. They had a 2 techs one with 28 years of experience and the other with 20 years and they could not explain why the SES light kept coming on. (they also brought in a tech from one of there other dealerships who had over 30 years experience and he was shocked with all the worked done and the SES light was still on) They called GM and GM was no help!!! They said it was the CAT and authorized the dealership to put on a new CAT for the second time at no charge. The service manager told me GM does not care once the car is over 8 years old unless its a recall! The Service manager has bent over backwards trying to fix this problem at the end he would wave all labor to put in the computer in I would just pay for the computer at cost. Since I did the spark plug non fouler trick the car is running much better and no SES light.