Replaced Fuel Pump and now P1133 & P0172

[ic3scrap3r]

I replaced the Fuel Pump with a new one from Napa this weekend. After driving about 30 miles the SES light comes on and I have pulled the following codes:
P1133, P1153, P0172, P0175
It is definitely running rough and I can smell the unburned fuel.

Any thoughts?

Thanks,
Matt

[BlazerLT]

Please post the year of your vehicle.

If it is a 1996+

Both driver and passenger manifold O2 sensors are seeing insufficient activity and are both running rich.

Have you been playing around with your MAF sensor at all?

Did they reset the computer after the new pump was installed?

[ic3scrap3r]

It is a 2000 with the 4.3. It is bone stock. I haven't done a thing. I didn't do anything under the hood during the pump replacement other than disconnect the battery. Could I have hooked something up backwards at the fuel pump and caused this?

Nothing was done to the computer other than retrieving these codes. I didn't even clear them.

-Matt

[BlazerLT]

Clean your MAF sensor by spraying brake cleaner through it to dissolve the grunge on the sensor wires.

But, before doing that, remove the negative battery cable for 10 minutes to reset the computer fuel curve so it can relearn with the new pump and better pressure.

[tom3]

Any chance you got the fuel return hose kinked at the tank? Might check fuel pressure to insure it's at spec. of about 60 psi.

[ic3scrap3r]

How can I tell if I have the two lines that are the same size on the right fittings? It has three with one large main line. The other two I am not sure of. One is labeled R and one isn't labeled. The large one that I have right is labeled F.

[Fireplug]

Or the pressure regulator craped out

[BlazerLT]

Don't worry aboutthe fuel lines, they are not the cause of this problem.

You are running rich, not lean.

Take some brake cleaner and spray inside of the MAF sensor and dissolve the gunk off of the MAF filaments inside of it. Just be careful, they are sensitive.

[ic3scrap3r]

Props to Tom3. The return line was kinked. When I started pulling the tank, this is the first thing I saw.
I didn't even have to pull it all the way. The metal line had been bent near the frame causing the plastic line to kink when the tank was moved back up.

Just given my mileage, I'm going to go ahead and clean the MAF sensor as suggested.

Thanks all for your replies!!

[BlazerLT]

Good that you found the kinked line but I doubt it will cause a lean condition.