I think I got these codes right, but they equate to Lean on banks one and two. Eventually, I get the codes for Bank 1 & 2 Oxygen sensors lack of switching indicating lean condition. When I start this truck up it revs to 2200 rpm and takes a bit to come down. I have done the basics as far as replacing the PCV hose, elbow etx. I have sprayed no less than three cans of carburetor cleaner all over this intake with no results. My LTFT is pegged at 25% at idle and about 0%-8% at 55 mph. Yes, I have a live data scanner. This of course indicates vacuum leak. I have isolated every vacuum port one at a time blocking it off to see if anything makes a difference. Nothing did but one. I removed the Idle Air Control Valve and used electrical tape to block the ports. I started the truck and it initially revved to 1500 RPM and quickly went to 700 rpm. Normal by my understanding. Once the computer goes to closed loop and the Oxygen sensors are working LTFT is 0% and STFT is 5% or so, Again, normal. At this point it is idling horribly and dies out occasionally and is less responsive to throttle inputs.
What else have I done?
* I have shot carburetor cleaner into a vacuum port to observe O2 sensor reaction for detecting rich mixture. It does on both banks. Conclusion: O2 sensors are working properly.
* I have allowed the same port to pull extra air in to to observe O2 sensor reaction for detecting lean condition. It does on both banks. Conclusion: O2 sensors are working properly.
* I have cleaned the Mass Air Flow Sensor. This should not be the problem but WTH? Why not?
* I replaced the Idle Air Control Valve... No change what so ever.
* I have gone through several of the trouble shooting pages for these codes with no luck.
Remaining suspects... EGR valve. DPFE sensor, I have not ruled out a cracked intake manifold (just have not found it). Bad vacuum canister (iffy at best). and Satan lives in this engine.
4 March 2017:
* Okay, I hooked up a new DPFE sensor... No change.
* I removed the vacuum tree from the passenger side of the intake and plugged the port at the manifold... No change
* I removed the vacuum hose from the brake booster and plugged it... No Change.
* I unplugged the NEW Idle air control valve electrical connection... It started normally and only revved to 1500 rpm briefly ten fell quickly to a rough low idle and died out within a minute or two. I plugged it back in and started it again and it revved to 2200 rpm and took a bit to come back down to about 1100. I never warmed it all the way up as I know my problem still exists if it revves to 2200 rpm at start up. Cold warm, hot, it does not matter. It goes to 2200 at first start.
* the saga continues.
Any experience out there that might be able to help?
Thanks in advance.
What else have I done?
* I have shot carburetor cleaner into a vacuum port to observe O2 sensor reaction for detecting rich mixture. It does on both banks. Conclusion: O2 sensors are working properly.
* I have allowed the same port to pull extra air in to to observe O2 sensor reaction for detecting lean condition. It does on both banks. Conclusion: O2 sensors are working properly.
* I have cleaned the Mass Air Flow Sensor. This should not be the problem but WTH? Why not?
* I replaced the Idle Air Control Valve... No change what so ever.
* I have gone through several of the trouble shooting pages for these codes with no luck.
Remaining suspects... EGR valve. DPFE sensor, I have not ruled out a cracked intake manifold (just have not found it). Bad vacuum canister (iffy at best). and Satan lives in this engine.
4 March 2017:
* Okay, I hooked up a new DPFE sensor... No change.
* I removed the vacuum tree from the passenger side of the intake and plugged the port at the manifold... No change
* I removed the vacuum hose from the brake booster and plugged it... No Change.
* I unplugged the NEW Idle air control valve electrical connection... It started normally and only revved to 1500 rpm briefly ten fell quickly to a rough low idle and died out within a minute or two. I plugged it back in and started it again and it revved to 2200 rpm and took a bit to come back down to about 1100. I never warmed it all the way up as I know my problem still exists if it revves to 2200 rpm at start up. Cold warm, hot, it does not matter. It goes to 2200 at first start.
* the saga continues.
Any experience out there that might be able to help?
Thanks in advance.
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