Z28 Engine Codes
#1
08-01-2008, 05:29 PM
Z28 Engine Codes
I have a 1997 Z28 with 3 codes. The code are P0174 (system to lean bank 2), P0304 (cylinder 4 misfire detected) and P0160 ( No activity bank 2 sensor 2). I pluged a scanner in and it shows bank2 sensor2 is active. I replaced the spark plugs and installed a new fuel filter but the codes come back. Can anyone help me with my issue?
Than You.
Than You.
#2
08-01-2008, 09:11 PM
RE: Z28 Engine Codes
The #4 cylinder misfire is probably the cause of all the other codes. The unburnt fuel from the misfire creates a rich exhaust condition on bank 2. This makes the PCM react by leaning out the fuel mixture and confusing the issue. Make sure cylinder 4 has a good spark an that the fuel injector is working properly. Check injector firing with a voltmeter or NOID lite. Unplug injector & see if condition changes. Also make sure the compression is good on #4 cyl. Bad compression = misfire.
#3
08-01-2008, 09:25 PM
RE: Z28 Engine Codes
ORIGINAL: z28pete
The #4 cylinder misfire is probably the cause of all the other codes. The unburnt fuel from the misfire creates a rich exhaust condition on bank 2. This makes the PCM react by leaning out the fuel mixture and confusing the issue. Make sure cylinder 4 has a good spark an that the fuel injector is working properly. Check injector firing with a voltmeter or NOID lite. Unplug injector & see if condition changes. Also make sure the compression is good on #4 cyl. Bad compression = misfire.
The #4 cylinder misfire is probably the cause of all the other codes. The unburnt fuel from the misfire creates a rich exhaust condition on bank 2. This makes the PCM react by leaning out the fuel mixture and confusing the issue. Make sure cylinder 4 has a good spark an that the fuel injector is working properly. Check injector firing with a voltmeter or NOID lite. Unplug injector & see if condition changes. Also make sure the compression is good on #4 cyl. Bad compression = misfire.
Thank again for your help.
#4
08-02-2008, 07:06 AM
RE: Z28 Engine Codes
Misfire is more prone under load as the plug is harder to fire as the gap resistance increases with pressure. As the engine speeds up the misfire is still there but harder to detect without the proper tools. Check or replace the wire for the #4 plug before you try anything else.
#5
08-02-2008, 11:00 AM
RE: Z28 Engine Codes
this isnt very time or cost effective but if its not the wire or injector you might have something similar to what i had, i had a bent end on the rotor so as it spun around it only made contact with certain pins on the cap so i had cylinders that werent firing. but i would definatly start out by checking what pete was saying because most of the time its the simpiliest thing that causes a car to go wrong and there is no point in going and spending money on parts that arent broken
#6
08-02-2008, 02:02 PM
RE: Z28 Engine Codes
Pete thank you for the #4 wire advice! I replace it and now the missfire code is gone and the lean bank2 code is also gone. Now i have to deal with the bank2 sensor2 no activity code. I guess i should replace the sensor even though the sensor is active and working when i check it with my scanner? Thank you to everyone for all your advice!!!!!
Jim
Jim
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