3100 starts, immediately dies

[96GPSE]

Hi all, new to the forum. Tons of great info here... but couldn't find anything on this:

96 Grand Prix w/3100. SES light came on a few days ago, so tonight I hooked up a scanner i borrowed from the local Checker. Pulled a code P0420 (something about inefficient catalytic converter). Cleared the code. Started the car to make sure SES light was off, and it was...but the car died about 4-5 seconds after starting. It now does that same thing every time - starts great but dies immediately. This happens even if I'm holding my foot on the gas.

 

Thoughts?

[jeremy]

clogged cat? ...just clearing a code doesn't solve the problem, it was thrown for a reason

[96GPSE]

I figured the code was either due to bad cat or a bad O2 sensor.

The car ran perfectly fine with the exception of the SES light...as soon as I cleared it I get this no run situation.

[19GT92]

PARK THE CAR do not drive it the cats clogged up and engine will occur if you keep driving it with a clogged cat. I'm suggesting to the op to have the car towed to the repair shop and a new cat installed and the 02's changed out for new ones cause when the cat blocks off it super heats the exhaust system up and more then likely it burnt the 02's out..

[Crazy K]

may I suggest.... remove both O2 sensors, both the one before and after the cat. see if the car will start... and see if all the exhaust tries to come out the pre-cat O2 port and not the post cat o2 port?

[96GPSE]

PARK THE CAR do not drive it

 

The car will not run long enough for me to drive it anywhere, so no worries about that.

 

may I suggest.... remove both O2 sensors, both the one before and after the cat. see if the car will start... and see if all the exhaust tries to come out the pre-cat O2 port and not the post cat o2 port?

 

This may be worth a shot...

I'm not really convinced it's a clogged cat though. I drove the car fine for a few days with the SES light on before clearing it, and it immediately starts up after dying. It seems to be linked to the clearing of the code...

[SigEpCutlass]

clogged cat? ...just clearing a code doesn't solve the problem, it was thrown for a reason

 

That'd be my guess if the code is "inefficient catalytic converter", as a clogged cat would be inefficient. Try Ken's suggestion & let us know what happens.

[Psych0matt]

do not drive if the cats clogged up and engine will occur if you keep driving it with a clogged cat.

 

so driving on a clogged cat will get me a new engine?

 

 

 

driving on a clogged cat wont do much, other than render it undriveable until you fix it. sounds like that's what's happening. My cavalier slowly got worse and worse and I basically had to have my parents in the van behind me push me to the shop

[Crazy K]

A clogged car can overheat the exhaust system. It can ruin the Oxygen sensor, and MELT VALVES AND CRACK HEADS.

[Psych0matt]

A clogged car can overheat the exhaust system. It can ruin the Oxygen sensor, and MELT VALVES AND CRACK HEADS.

 

well that's if you can actually drive on it, which in most cases you cant once it gets to that point, and before that point you'd still have decent flow

[Crazy K]

oh, not the last and not the least.... a clogged cat can set a car on fire. It can actually catch the carpet on fire through the radiated heat!

[96GPSE]

Thanks all for the replies. I may get to it this weekend, we'll see. Current MN weather -5F, no heated garage = car waiting to get fixed. It's booger freezin cold.