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C0265 C0291 C0223 and rough idle

Kb1984

New Member
Joined
Jul 15, 2019
Messages
3
Hello, I have an 03 Z71 with 99k miles on it. I was getting codes P0430, P0300, P0101 and loss of power. I replaced both O2 sensors for bank 2 as the code said. I cleaned the MAF, looked good. Reset the codes and ran the engine. Got rid of them all other than the P0300. Replaced spark plugs and wires, cleared codes, test drove and now I?m getting codes C0265, C0291, C0223 along with very rough idle and flashing check engine light. Can these issues cause the engine to run rough? I?m at a loss. I tried to search everything I could but couldn?t find an answer.
 
the codes make me think you have a def problem with the ABS :p i would visually inspect the wiring harness and connectors before you go buying modules.  :rolleyes: don't think these would be the cause of your rough idle.

C0223 - Right Front Wheel Speed Signal Erratic
could be a bad wheel speed sensor and would run around $60

C0265 - EBCM Relay Circuit
could be just a relay and would run around $10

C0291 - Lost Communications With BCM
could be a bad harness or Anti-Lock Brake System

ABS Control Module would run around $220 and a Body Control Module is around $340


check this thread...full of good info (y)
https://www.chevyavalanchefanclub.com/cafcna/index.php?topic=14789.msg1160928#msg1160928
 
A P0300 diagnostic code indicates a random or multiple misfire. and i think this is why you have a rough idle

causes could be a vacuum leak to dirty fuel injectors, low fuel pressure, a weak ignition coil, bad plug wires, or compression problems :rolleyes:

SnowWhiteAvalanche said:
This should help

http://www.obd-codes.com/p0300

and

http://www.obd-codes.com/p0351
 
Thanks Loggie, I?ll look into that. In the mean time I replaced the air filter, cleaned the throttle body and reset the codes. Took it for a test drive and around 35 mph got a flashing check engine light and all of the other codes are gone but now I have the P0300 for misfire and on my reader the ?cat? ?Eva? ?o2s? are flashing in red
 
Kb1984 said:
Thanks Loggie, I?ll look into that. In the mean time I replaced the air filter, cleaned the throttle body and reset the codes. Took it for a test drive and around 35 mph got a flashing check engine light and all of the other codes are gone but now I have the P0300 for misfire and on my reader the ?cat? ?Eva? ?o2s? are flashing in red

that code is a hard one to troubleshoot because it could be so many diff things.  A flashing light indicates that the problem is serious (n)

good luck (y)
 
Just figured I would update everyone. Ended up taking it to a shop, issue was bad cats. Had them replaced, all issues solved. All of the other codes c0233, c0265, and c0291 have disappeared and have not returned.
 
Good to hear!

Thanks for the update.

(y)
 
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