I have a 1999 Saturn SL2, and I have been doing a lot to it because I want this to be the last car I own (ha ha) Recently it is sputtering, and threatening to stall whenever I give it gas. It drives fine once I get going on the highway, but the second I give it gas, it begins sputtering and acting up. I have replaced the fuel filter about 3 days ago, It has a brand new MAP sensor, I replaced the plugs and wires, and did a fuel injection system cleaning on it. I has an entirely new exhaust system, including new converter. I haven't gotten around to scanning for codes yet though.

Any ideas?

Buy a can of BG44K from an auto parts store. The big chain stores might not carry it. Put it in at the gas station and fill the tank up. DO not put more fuel in until you get to 1/8 tank.

This will probably cure it by the end of the tank... and last for about 34,000 miles before you have to do it again. Problem is intake valve carbon buildup. I used to have one of those and loved it. The Saturn dealer Service manager is who told me to do that... (which was less then 1/2 what the dealer would charge) and it worked well until UI got rid of the car.

Most fuel injector cleaners are absolutely worthless. I had this carbon buildup happen despite using Chevron Techron every tankful.

Worst case...it won't work and you are out about $35 (roughly what BG44K costs depending on where you get it). It worked on mine...and your symptoms were similar to mine.

I suspect the Ignition Control Module (ICM) is failing. Try plugging your existing coil packs into a new ICM.

I suspect the Ignition Control Module (ICM) is failing. Try plugging your existing coil packs into a new ICM.

I replaced the ICM, and it is doing the same thing. I cleaned up the ground very good, and used die-electric grease, brand new ICM, same symptoms.

Check for codes. If nothing shows up, try Smoothy's suggestion. If the problem still persists, ensure the coil packs are good. To me, it smacks of an ignition problem. Did you use the same ACDelco plugs that came in the car?

Check for codes. If nothing shows up, try Smoothy's suggestion. If the problem still persists, ensure the coil packs are good. To me, it smacks of an ignition problem. Did you use the same ACDelco plugs that came in the car?

I try to buy better parts regardless of the cost. I forgot the brand of wires, but the plugs a Champion plugs. I thought about replacing them anyway. I also noticed sitting at a red light, in drive, it will sputter and act like it wants to stall. But, if I shift in to Neutral while I wait, it seems to be OK.

Engines are designed around a specific plug. It generally doesn't pay to use some other brand of plug than what came in the vehicle. For GM vehicles, you want to only use ACDelco. Champion plugs work best in Chrysler products. I would definitely install ACDelco plugs in your Saturn, gapped to spec. My bet is that installing the proper ACDelco plugs, gapped to spec., will solve the problem.

FYI, the wrong plugs can mimic a failing ICM.

Engines are designed around a specific plug. It generally doesn't pay to use some other brand of plug than what came in the vehicle. For GM vehicles, you want to only use ACDelco. Champion plugs work best in Chrysler products. I would definitely install ACDelco plugs in your Saturn, gapped to spec. My bet is that installing the proper ACDelco plugs, gapped to spec., will solve the problem.

FYI, the wrong plugs can mimic a failing ICM.


Ok, update on the car... I replaced the plugs with AC Delco plugs, and replaced the wires as well. I then replaced the ignition coil that went to cylinder 1, because there was a cylinder 1 misfire code. I have also replaced the fuel pump, and throttle position sensor, and Idle air control sensor. Below is a list of everything I have replaced on the car recently, in hopes of taking care of all issues:

IAC Sensor
Throttle position sensor
Battery (Interstate Brand)
ICM
Plugs (AC Delco)
Wires
Fuel Pump
Camshaft Position Sensor
MAP sensor (does not have a MAF sensor)
All fluids are good, and at max level, all synthetic fluids.
I did a fuel injection cleaning system on it

It will start and run, but as it warms up, it acts up, and as I slow down to a stop now, it will cut out as though I turned the key off... won't shutter, or shake or nothing, just PBBBTTT cuts out.

WHat did you use to do the fuel system cleaning (important because most of what's out there is nearly worthless for that).. and is it tripping any codes in the computer?

. Apply dielectric grease to the spark plug's porcelein and electrode.

. Apply dielectric grease to coil terminals.

. Check engine compression and look for intake manifold leaks. Did the engine ever overheat?