P0420 Diagnostic Trouble Code Discussion for May 2011
Catalyst Efficiency Below Normal (Bank 1)
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| Help Request | Posted | |
| 1999 Chevrolet Metro 1.0L No Start, Poor Idle Quality VIN: 2C1MR2267X P0420: Catlayst efficiency low. This vehicle was towed into our shop as a no start. Customer stated he thought the timing belt jumped, it died at a stop light and he managed to get it started long enough to limp it off the road. He tried moving the distributor to get it to start with no luck... |
May 06, 2011 | |
| 2001 Pontiac Grand Prix GT 3.8L MIL Lamp on VIN: 1G2WP52K91 P0420: Catalyst System Bank 1 Low Efficiency. Car came in with cat code p0420.Check car and found rear o2 sensor damaged replaced and code came back.Fuel trims good.Graphed sensors and rear o2 stays flat but does move up and down when decelerating .Front o2 seems to be working okay.Freeze frame data show ... |
May 17, 2011 |
