I've got a 1996 Geo Prizm, with automatic transmission. I was on my way home last night, and suddenly the engine got loud, like I was missing a muffler or catalytic converter. I stopped, took a look at everything underneath, and it was all still there and together. I was about a mile from the next exit, so I thought I'd try to drive off the highway.

I started it back up, it didn't start easy... it would then stall if I took my foot off the gas. There was a big loss of power. Just before I got to the exit (about a mile later), I lost power completely and the car started slowing down. The car stalled, and the oil light may have come on... I'm not sure if it was on right before it stalled, or after along with the battery light (it happened kind of fast).

Now when I try to start it, it cranks, but will not turn over. I can hear the fuel pump come on.

I did have a problem a few weeks ago, with all the snow, my exhaust system was disconnected right before the catalytic converter. I drove it home from work, and to the hardware store for some bolts, like that. I was told that not having the back pressure from the catalytic converter and muffler can wear down the engine pretty quickly; I drove it about 10 miles that way before I was able to fix it.

Any advice would be appreciated:) My sister's boyfriend is a mechanic, but he isn't here to take a look for me, lol.

Slight update:

I talked to the mechanic, but I think he missed some of what I was saying... he suggested it might be a bad fuel pump, and he's going to try to make it out here to look at it for me today.

I just went out and tried it, after letting it sit over night. It fired up as soon as I turned the key, but it idled very... badly? Like it was misfiring, very... choppy. It stalled after about 5 seconds. It was also louder than normal.

Very few fuel pumps fail and need replacing on modern-day cars, even though many get replaced. Instead, I would go over the basic electrical system and replace:

. Spark plugs (exact NGK plugs that came in the car), rotor, and distributor cap.

. Ignition Control Module (ICM):

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. Coil:

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I recommend replacing ICMs and coils every 120,000 miles or 10 years, whichever comes first. It's likely the spark plugs or ICM is causing the problems. 90%+ of starting/running problems are electrical-related, not fuel. If you haven't replaced the fuel filter in the last 60,000 miles, however, I would replace it:

Fuel filter:

http://shop.advanceautoparts.com/Pro...Type=4&PTSet=A

I have to leave to your judgment whether the catalytic converter issue is a contributing factor or not. I can't begin to assess that from here.

I would think the catalytic converter would be fine... that was a few weeks ago, and after I got it back together the check engine light went off and has been working fine since. Just thought it may have contributed to something else.

Thanks for all the info! I'll check out the spark plugs first, and go from there. Unfortunately I don't have many tools here at my apartment, so it's going to be a few days. I'll let you know how it turns out.

That's a good plan.

Well, it had spark. That pretty much eliminates what I might have been able to do in my apartment parking lot in the snow, lol. The car is at a mechanic shop now... they're going to look at it tomorrow.

The verdict:
Timing is off, belt is worn.
Cylinder 1 is low on compression, it's 75, they said it should be around 140.
Cylinder 3 has no compression.
Blown head gasket.
Knock in engine.

They quoted me $1,500-$2,500 to fix it. I only paid $1,200 for the car, a year ago...

Daaaaaang.

Anser:for I've got a 1996 Geo Prizm the won't start .
It is you crank position sensor