I have a chevy prizm, and I have to pass emissions with gateway clean air and I have three OBD codes
P0300 Random/Multiple Cylinder Misfire detected
P0303 Cylinder 3 Misfire Detected
P0171 System Too Lean Bank 1
P0420 Catalyst System Efficency Below Threshold Bank 1
car is sputtering and shaking, have replaced sparkplugs,air filter just wondering what it could be?
2007-01-08 16:54:32 · 1 answers · asked by chrissybe26 2 in Cars & Transportation ➔ Maintenance & Repairs
Bad coil will cause the random misfiring. #3 may have a bad wire. Cylinder not firing on one bank will result in too lean a mixture, because the computer shuts off injector current to cylinder with no fire.
Catalyst will be over loaded with unburned hydrocarbons, because the random misfiring will not trigger the computer to shut off the injector circuit.
2007-01-09 10:45:35 · answer #1 · answered by eferrell01 7 · 0⤊ 0⤋
P0303 Cylinder 3 Misfire Detected
2016-11-13 06:27:57 · answer #2 · answered by ? 4 · 0⤊ 0⤋
The previous are good answers, I recently ran across an Olds. that had some similar codes/performance. Turned out that the secondary winding on one of the coils was shorted (that's bad). They are usually easy to access/check. If you have a multi-meter, or have a friend that does, use it to check the resistance on your coils. Primary winding should have very low resistance somethin like .3 to 1 ohm. The secondary winding needs to have much higher resistance somewhere in the nieghborhood of 20K ohms. This varies from vehicle to vehicle, but the ranges are right, primary, check in the ohm range, secondary, check in the kilo-ohm range. If there is an open in the primary winding it's bad, a short in the secondary, like if it is showing less than 8k ohms resistance, that's bad (It will be obvious). Also, the trouble codes are not always accurate to the cylinder numbers, so check all coils. (I'm not sure how many are on there, if it's a four cyl. probably only 2, but I'm not sure) If I can be of further assistance, feel free to contact me, Good luck, Scott
2007-01-08 18:01:11 · answer #3 · answered by Cougar_SRC 2 · 0⤊ 0⤋
pull out #3 spark plug, if its white and dry you may have a bad injector or an intake gasket leak on that runner, if its black and wet you may have a bad valve or a spark problem and just need a tuneup. you have to get the engine to run smooth and clear the codes to see if the 171 or 420 come back.
2007-01-08 17:23:25 · answer #4 · answered by quickcuda69 3 · 0⤊ 0⤋
If the Prizm uses ignition coils that might need replacing too. If not then try replacing the spark plug wires, rotor and distributor cap.
2007-01-08 17:44:35 · answer #5 · answered by The Piper 1 · 0⤊ 0⤋