Exhaust failure, 1980.

[mixybro4]

I had just got my new borla exhaust system up and it was sounding good, smoking kinda bad at times. But it was at about 2000 RPMs. And it just sputtered and died with a popping noise and shut off. Waited a bit. It fired and ran and died in like 5 seconds. The dash says OSX, maybe an O2 sensor failure? Any ideas

[harborman]

Sounds like something along those lines. If it ran fine before your new exhaust and this is all you did, then something changed for sure.

[mixybro4]

Yeah it ran pretty well before hand. It didn't really have anything past the cat, and now this new borla. It doesn't stay running for more than 5 seconds

[mixybro4]

Do you guys have any ideas of what it could be?

[MPDano]

What condition is the cat in? Could be plugged?

[mixybro4]

Cat is original. Pretty rusted on the outside.

[MPDano]

Remove it and then start it. If it lasts more than 5 seconds, than there is your issue. If your not required in your state, then put a straight pipe and clamps in it's place.

[Danglerb]

When you changed the exhaust did you mess with the O2 sensor, maybe unplug it? OSX means a problem with the O2 sensor unless it going out once you tap the gas a little.

Gas in the tank?
Fuel pump running?

What color was the smoke?

[harborman]

Originally Posted by mixybro4

Do you guys have any ideas of what it could be?

I guess my point was that when work is done, sometimes other things are disturbed, like the O2 and wiring. Seems the guys are pointing you in the correct direction. Let us know how it turns out.

[mixybro4]

I did not do anything to the O2 sensor. Smoke was black at first, probably burning off some of the nasty stuff in the engine, turned clear later. Perhaps something happened to the O2 sensor due to all the new back pressure because it did not have any exhaust except the cat a first. Will a bad O2 sensor stop the car from running?

[mixybro4]

Okay started up today without any problems. I did nothing, took off the back half of the new exhaust system though.

[mixybro4]

Okay it shut off again, still saying OXS. Doesn't seem to run at all now.

[Fixer]

Sounds like what my '83 did when the alarm acted up due to removal of just about everything inside the car.

Had to bypass it and it fired right up. Check glove box, door light switches..

Doesn't sound like something your exhaust would cause.

[kelanel]

Just for laughs, to rule out the o2 sensor, have you tried putting the car in open loop mode by unplugging the wire at the passenger footwell?

[mixybro4]

Which wire to be exact?

[kelanel]

something like this (green wire with connector), color may vary from year to year. but it feeds down the same spot

[mixybro4]

That did not fix it, still says OXS. Just sits there and grumbles, not wanting to stay running. Could it be the ignition box?

[mixybro4]

I'm ya a loss right now. Taking off the cat right now, you really think that could be it

[mixybro4]

Okay so I started cranking the engine and it started firing barely and I held the gas petal down and I was still holding the key over to keep it going(probably not very good on the starter) but once it finally got to 1000rpms the OXS shut off. And it puts out tons of exhaust. Is there any possibility it could be a bad ignition coil? I believe it to be the original one, and I have replaced everything else in the ignition system besides the coil and the computer.

[harborman]

When a 928 floods out, it floods out but good. Not sure about your problem but after I replaced my fuel lines it would not start. Plugs were all wet. Finally I just put the peddle to the floor, kept cranking and it started with a big cloud of smoke.