99 Chevy

I posted a while back about one of the many problems I had with my 99 Chevy.

We took it to get the check engine codes looked at. The codes that popped up are

p0452, P0171, P0420 and P0174.

We are still having a problem with the driveability. When we stop at a light and then go to step on the gas it bogs down and does not want to go and to fix this we turn the car off for about 10 seconds and then it acts like nothings wrong.

We did get the fuel pump replaced a year ago and my husband said they told him that they had to cut the wiring for the fuel pump because it didnt match the new pump. I don’t know if that has anything to do with any of the problems, but just thought I would throw it in there in case.

Back to my main question though, is would those codes have anything to do with the way its acting when i give it gas? And would anyone know what could be the cause. Thanks!!

Sorry for the double post but its a Chevy Suburban.

I’ll lay out the code numbers definitions ans perhaps a qualified tech can do better than I could.

Could the codes have anything to do with the way it’s acting? Absolutely.

PO171…system too lean, bank1

PO174…System too lean, bank 2

PO420…Catalyst system efficiency below threshold

PO452…Evaporative emission control system, pressure sensor low output

This truck is running lean according to codes P0171 and P0174. This is typically a fuel delivery problem or an air leak, like a bad intake manifold gasket or a large vacuum line leak.

This truck should have a fuel pressure test port to help confirm the operation of the fuel pump. Is this a Vortec engine? If so, the CFI unit is trouble prone, and can easily cause lean conditions. If it is EFI, then you can listen to each fuel injector operate but using a mechanic’s stethescope, or use the poor man’s version, a long screwdriver with the handle cupped to your ear. All 8 injectors should sound very similar as they tick.

Vacuum and air intake leaks can make it hard for the truck to maintain idle. Is it revving up and down?