Power loss and backfires?

STEVEHIX

MEMBER
1999 FORD EXPLORER
4.0L
V6
2WD
MANUAL
180,000 MILES

I replaced cats with strait pipe but included flanges with o2 sensors. I changed plugs air and fuel filters, plug wires, cam position sensor, EGR solenoid, cleaned throttle body, MAF sensor, cleaned injectors, replaced one of the temperature sensors, and cleaned all connectors and greased them. I got the vehicle to idle and drive but it has no power and backfires it actually runs better if I pull the PCV.

Thursday, November 16th, 2023 AT 9:52 AM

1 Reply

JACOBANDNICKOLAS

MECHANIC
110,176 POSTS

Hi,

Is the check engine light staying on? If so, have you checked for diagnostic trouble codes?

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Keep in mind, the oxygen sensors' signals are going to be off because there will be no change between the upstream and downstream sensors. The catalytic converter makes the difference. This will result in the air/fuel mixture causing issues.

Do you have a live data scan tool? If you do, check the short-term fuel trims and let me know what they are. Do this when the engine is at operating temperature.

Next, watch how the oxygen sensors' voltages are changing. They should be between 0.1 and 1.0v.

Let me know.

Joe

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Thursday, November 16th, 2023 AT 9:12 PM