Why is my cars converter cherry red and running rough

100

Asked by Oct 20, 2013 at 05:25 PM about the 1996 Pontiac Grand Am 2 Dr GT Coupe

Question type: Maintenance & Repair

1996 Pontiac Grand Am 4 cylinder 2.4 car stalled was running really rough and firework odor and sounded like a lawnmower and had a exhaust gas smell, low and behold made it home to discover a cherry red catalatic converter and smoke, gave new spark plugs replaced ignition housing because it was cracked gave oil change and replaced catalatic converter, started up engine ran smooth but car still sounded like lawnmower and strong exhaust smell and greyish smoke coming out of tailpipe took around block came back ran rough sounded loud and when got back new converter cherry red again what else could be the problem

17 Answers

264,405

A red hot glowing cat is a sign of the engine dumping unburt fuel into the exhaust, and the fuel is burning in the cats, eventually clogging them. Fix your ignition/fuel system first. Check for misfires. Possibly one of your injectors might be leaking.

6 of 6 people found this helpful.
100

So should I start by changing the ignition coils, then if that don't work change the fuel injectors I forgot to mention there was a slight gas smell and when car was idling it was if it idled up on its own almost like someone bumped the gas petal.

1 of 1 people found this helpful.
264,405

Since you mentioned the idle going up and like someone hitting the gas, that sounds like fuel is dumping in when you don't want it too or a leaking fuel injector......http://www.ehow.com/how_7760596_check-leaking-fuel-injector.html

2 of 2 people found this helpful.
100

would the ignition coils being bad cause such issues or not at all

1 of 1 people found this helpful.
100

I was looking the page on how to check for fuel injector leakage but I don't have a fuel gauge is there anything else I can use

2 of 2 people found this helpful.
100

can it be my o2 sensor would this going bad cause fuel to be dumped?

100

also engine light don't stay on it is just blinking real fast

2 of 2 people found this helpful.
4,885

You cannot diagnose a fuel mixture issue on a '96 anything, without OBD code. Pep Boys will check it for free, that's a start. EFI will run rich for any number of reasons. Leaking injectors is possible but unlikely, INHO. O2 sensor, air temp sensor, mass air, fuel filter. An exhaust leak before the Cat temp sensor can cause a "false" lean condition that the computer attempts to correct. The fact that your Engine light is blinking indicates an engine code that is causing the computer to compensate in ways that are harmful to the engine.

2 of 2 people found this helpful.
100

but im scared to drive it anywhere because I only went to end of block and cat was cherry red and smelled like burning metal is it safe to drive it like that?

1 of 1 people found this helpful.
4,885

It is not safe to drive like that, cat fires are all too common. Get it towed.

2 of 2 people found this helpful.
100

ok rented scanner these are the codes I got p0300 p0420 p1258 p1404 p0174 p0405 p0441 please help me figure this out

2 of 2 people found this helpful.
100

ok rented scanner these are the codes I got p0300 p0420 p1258 p1404 p0174 p0405 p0441 please help me figure this out

1 of 1 people found this helpful.

P0300 Random misfire...P1258 engine coolant overheated...P1404 EGR failure ..P0174 fuel/air ratio too lean P0405 another EGR problem ...P0441 EVAP not purging. As Norm stated, do NOT drive the car. There are multiple issues you may decide to not let this car become a money pit...consider trading it in for a Toyota. Or something like that, stay away from Chrysler products and Kia/Hyundai

2 of 2 people found this helpful.

PS a steady CEL means get your car checked when convenient, blinking CEL means NOW ,,,and welcome back Norm good to see you...we need guys like you that know what they are talking about, don't make yourself scarce...~David

3 of 3 people found this helpful.
4,885

Thanks for posting the scanner code, David! EGR failure will have a cascade effect and is probably triggering the other codes. Bad EVAP purging is also a consequence of rich condition............... If you want to take a gamble that it's a simple EGR issue, you can get the EGR for that car for about $60. You could also just clean the one you've got but if the trouble code remains you won't know if you did a bad cleaning job or it's something else. Spring for the new EGR. It's not that hard to get out. You might even find a video on YouTube (hint)............. The Pontiac 4 cylinder isn't going to give you many more years of trouble-free driving, so you might be doing this work just to unload the car. Good luck!

1 of 1 people found this helpful.
75

I aggree that there is un burnt gas in exhaust which prevents the cat from removing the NOX from the exhaust. Maybe timing issue or coil, injectors or injection control module. Po300 misfire is not specific as to the cause.

Pull the injectors, hook to 12 volt bat. charger, see if solenoid clicks open, clean with spray break cleaner and blow out with air gun.Spray should be heavy mist, replace 'O' rings and reinstall. Clear ECM by disconnecting bat cables for 5 min. and ground hot side to clear dashpots. Reconnect an run normal operation.

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