PO 151 and PO131 on 1999 Chevy Suburban

1999 Chevy Suburban K1500, The fuel pumpwas replaced in April. The vehicle ran fine. The vehicle was givien to me. I replaced the air filter and start loosing compression up hills after a short time of driving. Rplaced fuel filter, had injectors cleaned. I heard that a new wiring harness has to be installed for the new fuel pump. I bought the part but the connector for the new harness is wrong. Finally after months of driving the check engine light came on. It gave codes PO151 and PO131. Any advice would be helpful.

The harness that you are referring to is a connector at the fuel pump, On alot of GMs when the pump fails the connector melts and leads to poor contacts and voltage drops causing repeat failures of the pump and still low fuel pressure! I doubt it would cause the codes you're experincing it sounds like either a couple of o2's are inorder or you have a restrictted catalytic converter. It's very common on GM trucks for them to plug up and generate 02 sensor codes.

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