Cadillac Catera and Cimarron Forum Discussion, 1999 Catera problems NEED HELP! in Past Cadillac Vehicle Discussion; OK I see that alot of people are having troubles with their Catera's miss firing.
Well mine has all the ...
OK I see that alot of people are having troubles with their Catera's miss firing.
Well mine has all the same syptoms but I do not have oil leaking from my valve covers. I do know it smells like straight gas coming from my exhaust and well the car use to sputter every now and then till it got warmed up. now it really don't move because when you press on the gas it misfires so bad. I took it to the local GM dealer and they had it all day at $65bucks an hour and could not figure it out. All they said was order a new computer for it and we will go from there. Well the new PC cost almost $500 then you have to pay $100 to get the new PC programed. Then they had it all day again and still by the end of the day the day they did not know what was wrong so I was mad and removed it from there shop and refuse to take it back there. I will just work off the web forums to get it resolved then pay a local shade tree guy to do the work. I do not have all the problems codes as of yet but some of them are PO135, PO155, 300,301,302,303,304 I am going to go buy my own code reader this next week when I get paid. But I thought I would see what your input might be. Thanks for any help you can offer.
The 99 Catera's are the first year for Coil on Plug ignition; so theres no wires except for the power going to the coils and since all the plugs are connected together on a bridge; off the wall 1 2 3 4 misfiring doesnt seem right. Each are on opposite sides of the engine.
After the car has sit overnight or atleast a few hours (till its cold), take one of the sparkplugs out before you start it and "smell" for raw fuel both on the plug and in the combustion chamber. This may rule out a bad fuel pressure regulator or leaky injectors.
Now concerning the oxygen sensor codes..
The the first set of o2 sensors on your car (i believe these are before the catalytic converters) the computer is saying its malfunctioning. Now, you say it runs rich and sputters before it warms up... The o2 sensors have to give off a specific voltage vs the amount of airflow the engine is getting; theres a set range dependant on this. The code means that they're taking too long to reach that point (it has a heater to adjust). And since the car regulates its air/fuel and emissions off of the o2 sensors, malfunctiong ones sometimes can cause it to run so rich that it sputter or misfire - too much fuel vs air comming in.
What are the other codes..? Might be more to the equation here.
yeah the problem was a mass air flow sensor I finally figured it out just unpluged it and the car ran fine bought a new one from the dealer for $187 now just have to buy new O2 sensors then all back to normal.