Both banks lean

[reomack]

2000, 3.o, three new o2 sensorscodes 1131, 1151, and 171. Feels like it is running on 3 or 4 cylinders. Compression is good on all six. Anyone have any ideas about what it might be?

 

[jonlax]

When you have a lean condition it usually means that you have un metered air, check your intake manifold and all areas after the MAF for leaks.

 

[reomack]

Thank you. It does run like it has a msiive vacuum leak, now that you clued me.

 

[Jack Flash]

a bad EGR will create lots of problems. check the operation of the EGR valve.

 

[reomack]

If the EGR is malfunctioning, I think it is because of the vacuum leak. I don't have a vacuum gage but pulling off a line and putting my finger just over it I can feel a pulsing, then when I shut it off altogether with my finger, I don't really feel any suction at all. I'm all but positive that the upper manifold gasket is the culprit.

 

[reomack]

today I replaced the upper manifold gasket. was not the problem. Still have codes 1131 and 1151. fuel pump sounds normal, runs for a second after turning key on but not starting engine, then turns off. truck uses lots of gas. no power when it runs at all. will not idle. i will change fuel filter tomorrow. today checked the EGR valve and it was cool to the touch so isn't stuck open. checked the DFPe sensor-checks good. checked the EGR vacuum solenoid-checks good. Don't have a fuel pressure gage so can't do a good check on fuel system pressure. plugs and wires are good-no ign codes. HELP!!!

 

[Tbars4]

..You would get more responses if you had your location under your name..

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1

P1151 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2

P0171 System too Lean (Bank 1)

I would chase the p0171 first..

 

[reomack]

Mostly fixed it. Found two of my own screw ups. Drivers side PCV was out. Also the vacuum fitting between the drivers side of the intake and the firewall was just next to rather than actually on the the manifold. Have now replaced the plugs and wires, the fuel filter, all 3 O2 sensors, and the manifold plenum gasket. Runs better but will probably replace the coil too.

 

[zekew64]

Have you disconnected the battery to reset the codes? If you don't do that, the computer will won't take into account the fact that the problem(s) have been fixed.

As such, your truck won't adapt to them, and will still feel like the issue still exists.

As for the coil, check the resistance of the primary and secondary circuits with a multimeter; if they are out of spec, replace them.

The coil should have a measurement of:

Primary: 0.3 to 1.0 ohms
Secondary: 6.5k-ohms to 11.5k-ohms

 

[reomack]

Not yet. I'm away visiting family right now. Will get back to it after the 16th and will report back then. Thanks