I am looking for the codes for a 90 Chevy Caprice. Are they the same as the bonnie? Thought they might be since theyre both gm, but I pulled a 33 and a 44 from my caprice and the 44 makes sense from the description of the code 44 on the bonnie but there isnt a 33 listed. Does anyone know where i might find code definitions for this car?

Here, try this site:

GM Trouble Code Info

Code 33 is your MAP sensor

Thanks alot. This is what it says for my car....

33 MAP sensor signal voltage was too high (low vacuum) for 5 seconds when throttle opening was under 4%.

44 Oxygen sensor voltage was under 0.25 volts for 50 seconds of closed loop operation. On Brougham models the oxygen sensor voltage was under 0.2 volts.

Does that mean that both sensors need to be replaced? or does it mean theres an electrical problem somewhere? Neither one of those was really what I was looking for... I think the fuel pump is going out and I was hoping Id get a code that said it was running lean or something along those lines.

Then again I suppose its possible that the catalytic converter is getting clogged as it just barely passed its last emmissions inspection, and its been my experience that the oxygen sensor doesn't usually go out unless the cat is clogged.

What engine you have in that Caprice?

305 TBI... I think im a bit confused as to what a map sensor does? Maybe those two sensors are causing my problems entirely... The car doesnt want to move at all after it has been sitting for any longer than 10 mins, after running for awhile the problems seem to go away, but when you first try to give it gas it starts to stall out, eventually it will accellerate very slowly until youve been driving for 10-20 mins and everything usually returns to normal.

O.k. now for my next question. Don't know if anyone will know the answer, but where is the map sensor located? Also is this something I should buy new, or would a trip to the junkyard work? I'm on a tight budget with christmas comming up.

OK, just wanted to chime in with a couple things to consider. Yes, your MAP sensor may indeed be dead and causing the bad O2 sensor readings. But before replacing it, take a reall close look at your exhaust manifolds.

Leaking exhaust manifold gaskets and cracked exhaust manifolds can cause the MAP to read low pressure problem. Remember, the exhaust manifold is not always under pressure, the pulsing nature of the exhaust causes negative pressure waves to draw air into the manifold. The resulting bad readings at the MAP could cause the O2 sensor readings.

Similarly, low fuel pressure can result in the low O2 sensor readings. You would need to test your fuel pressure to verify that.

From Autozone . com:

Looks roughly like this:

Well Ive suspected the fuel pump may be going for awhile now... I know how to check fuel pressure on a bonne... but this car is different... any idea how I check fuel pressure on it?

Also I am gonna change the fuel filter as soon as stupid auto zone gets it in, tommorow hopefully. I suppose its possible the fuel filter is starting to get clogged... especially since I ran the car out of gas a couple times.

As for checking the manifolds... should I do this with the car off or on? I don't know if this matters or not, but this problem just popped up all of a sudden. Its not something that gradually came on. Just one day I started the car and it was doing that. I don't know if that might help to figure out the problem or not.

Thanks alot for trying to help. Despite the car not being a bonne... or even a relative of the bonne. To be honest I don't like the caprice too much. I'm gonna try to sell it in January, and hopefully I will be buying another bonne (if I can find a */c model in my price range). If not then im going small car with a stick shift.