Isuzu SUV Forum banner
1 - 3 of 3 Posts

·
Registered
Joined
·
12,374 Posts
P1171 is a failure detected during a power enrichment test which indicates there is a fuel delivery problem. It is highly probable the misfire and O2 sensor issues are related to the fuel delivery problem. You may have a clogged fuel filter or defective fuel pressure regulator or defective fuel pump or water in the fuel.
 

·
Registered
Joined
·
12,374 Posts
If the filter has been replaced, measure the fuel pressure at the test port with a gauge, it should be about 36 PSI at idle. Pour a16 Oz can of SeaFoam motor treatment into the gas tank, it can help if you have water in the fuel. The backfiring and downstream 02 sensor problems can be caused by water in the fuel, it does not take much water to cause problems. You can worry about the cats after you solve the fuel problem.
 

·
Registered
Joined
·
12,374 Posts
You have a left and right side catalytic converter and four O2 sensors. The two O2 sensors closest to the engine, B1S1 and B2S1, control the fuel mixture. The two located after the catalytic converters, B1S2 and B2S2, monitor the performance of the catalyst. Prolonged driving under misfire conditions can cause the catalyst to melt down and destroy the converter. Replacement is about $500 each plus labor.
 
1 - 3 of 3 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top