O2 malfunction?

[osaltyone]

So I got my truck running with the 5.3, took it out for a spin and when I ease in to the throttle it is great, but if I punch it, the truck cuts out and seems like it wants to die, like a limp mode.

I get the codes shown from DashCmd when that happens. both banks seem to run lean, then rich.. Not sure what could be the cause. Any ideas? 5.3 with the fuel regulator on the rail.

[BR3W CITY]

pre-02 exhaust leak causes extra "Clean" air in exhaust which the 02 then measures...after reading lean it then tries to compensate a dumps fuel into the motor, causing it to run rich.
It's the motor playing a balancing act.

Check header flange gaskets and the manifold to downpipe (or catpipe) connection.

[osaltyone]

I will go pick up a new set of gaskets. I reused the ones from the LS manifolds when I got them. I don't hear an exhaust leak and all bolts are tight.

Anyone know how to wire the O2 sensor?
I have a set of sensors that I got for the rear, but deleted them in the tune. The wires in the harness are Green, pink, tan and purple, but my other O2 has 2 white, grey and black. I don't want to hook them up wrong and mess something up.

[BR3W CITY]

Check this link out, its a PDF of wiring instructions for Bosch Universal sensors, there is a color chart at the bottom if it helps.

http://www.vaglinks.com/VAGLinks_Com...orInstall2.pdf


I know VagLinks sounds like a weird site...i had second thoughts before clicking but it's legit.

[osaltyone]

swapped the O2 and cleared the codes. It seems to idle better, doesn't sound like it has a lope in the cam, but still stutters when I get on it under load. I'll pick up those gaskets tomorrow.

Wiring I used
white to pink
white to green
black to purple
grey to tan

[clinebarger]

Originally Posted by osaltyone

swapped the O2 and cleared the codes. It seems to idle better, doesn't sound like it has a lope in the cam, but still stutters when I get on it under load. I'll pick up those gaskets tomorrow.

Wiring I used
white to pink
white to green
black to purple
grey to tan

It looks correct.....

Bank 1 sensor 1.
Purple/white.....O2 signal wire
Tan.................O2 ground
Black/White......O2 heater control curcuit (ground)
Pink.................O2 heater power

Bank 2 sensor 1.
Purple..............O2 signal wire
Tan.................O2 ground
Light green.......O2 heater control
Pink.................O2 heater power

Bosch 4 wire universal
Black..............O2 signal
Grey...............O2 ground
The polarity on the White heater wires doesnt matter.

If you had O2 problems......P0131 & P0151 are the codes that would be set along with codes you have.

Make double sure the O2 wiring leads arent crossed....Bank 1 reading bank 2 & bank 2 reading bank 1.
Check for vacuum leaks.
Check fuel pressure 58 psi.

[osaltyone]

Originally Posted by clinebarger

It looks correct.....

Bank 1 sensor 1.
Purple/white.....O2 signal wire
Tan.................O2 ground
Black/White......O2 heater control curcuit (ground)
Pink.................O2 heater power

Bank 2 sensor 1.
Purple..............O2 signal wire
Tan.................O2 ground
Light green.......O2 heater control
Pink.................O2 heater power

Bosch 4 wire universal
Black..............O2 signal
Grey...............O2 ground
The polarity on the White heater wires doesnt matter.

If you had O2 problems......P0131 & P0151 are the codes that would be set along with codes you have.

Make double sure the O2 wiring leads arent crossed....Bank 1 reading bank 2 & bank 2 reading bank 1.
Check for vacuum leaks.
Check fuel pressure 58 psi.

Thanks! I wonder if I have a leak somewhere. I can hear a slight hiss, but not sure if that is my big ol cold air intake or the intake manifold. I will go through it tomorrow and tighten all the bolts on the intake manifold to see if that stops the stumble I am getting when I step on the throttle hard.

[BR3W CITY]

you can check around the evap solenoid on the intake, sometimes it can be cracked (especially on a pullout motor) and leaks there...also make sure you check the nipples on the TB for a leak there...a little starting fluid will go a long way looking for vac leaks.

[Gunny Davis]

Had very similar problem with my 5.3 swap w cold air intake...
Turns out I believe the filter oil, from intake filter was yuking up the MAF. So I picked up som MAF cleaner from AutoZone and runs like a champ. no problems since. Its worth a shot

[osaltyone]

Looks like it might be my fuel filter. I just grabbed one from my drawer when I was running the lines and it might not have been for fuel injection and might be clogged. I was spraying starting fluid looking for a leak and could not find one, went to get back in the truck to pull it in the garage and it died when I stepped on the pedal and would not start again unless I shoot starting fluid in the intake. Ordered a new filter from Jegs, so we will see.

[osaltyone]

swapped the filter yesterday and took a bit to get it started, but ran great...that is until I noticed a large puddle of fuel under the truck. Guess I didn't tighten the clamp as tight as it should have been on the pump fittings. fixed that and all is good! runs great and no lean issues. Actually no codes at all!