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rpmdiag, Tech and Instructor
Category: Nissan
Satisfied Customers: 6698
Experience:  Since 1975
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2000 nissan sentra gxe automatic qg18de codes po420/po430/p0505

Customer Question

2000 nissan sentra gxe automatic qg18de codes po420/po430/p0505 1st two plugs towards front of motor are black last two to rite look fine. runs great when plugs are clean .when two left plugs get dirty/fouled car wont start unless you give /pump lots of gass/clean plugs starts great/runs great.then starts all over again about every 500 miles.clean plugs beceause have bought to many.need to fix problem.
Submitted: 4 years ago.
Category: Nissan
Expert:  rpmdiag replied 4 years ago.

rpmdiag :

Hi, I'm Ron and I can help you. It looks like the cats are bad or the O2's are reading wrong. This problem needs to be corrected first. Make certain the O2'sare working right, don'y worry about the cats yet, we need to get this in fuel control first. If the O2's are good, then weneed to lookfor leaky fuel injectors in those cylinders. See attachment of how a good O2 should look in each segment. Hope this helps, Ron

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