So after doing my head gaskets I've been fighting with codes on Bank 1. That and a recurring coolant leak at the throttle body heater. I thought I finally had that tackled with 2 clamps per hose but they seemed to loosen up a bit and leak again. What a hassle that thing is.


The codes I keep getting are indicative of problems with the sensor readings and running lean like P1171 and P0171. I've also gotten a P1300. I have replaced the upstream sensor on the driver's side and when it's running I see the rear sensor voltage sitting very low, like .01 to .05 volts, then when I rev the engine it jumps up much higher like .65. On the passenger side, it tends to read right around .65. The fronts are reading as I would expect. I had a cracked flange on the driver's side which I had welded up a few weeks ago and it is quiet now but I was still getting codes.


I decided to try a smoke test. I put a glove over the inlet, pulled the PCV line from the passenger side and plugged it, then connected a hose from one of those cheap transfer pumps to the nipple on the intake. I lite up a cheap Garcia Vega and stuck it in the pump inlet and started pumping. I got lots of smoke out of the adjacent vacuum fitting, that stupid one with the o-ring. I pulled it a apart and tried to find a replacement o-ring in my kit with no luck. I found an AC one that was close so I put it back together ands in the process broke the hard plastic vacuum line right where it expands a little bit. I ultimately used some plumbers epoxy to fit a nipple in the fitting to hook up a piece of rubber hose which I then connected to the hard plastic line. What a stupid, fussy design that o-ring setup is. What is the best way to fix it now? I'm not too sure how long my epoxy and plastic nipple setup will hold up.


Plus, my post cat O2 readings remained virtually unchanged. This is annoying. I have cleaned the MAF, fixed the only vacuum leak I found. When I had the engine apart, I ran some injector cleaner through the injectors and they appeared to be flowing beautifully. The truck runs awesome and I can't tell there is anything wrong. Any suggestions on where to look next?

 

did you try spraying around all the injectors with carb cleaner?

 

What he said. Or when you did the head gaskets, did you replace the o-rings on the injectors? Most head gasket kits I've seen come with them. Heck, most come with o-rings for like 3 different kinds of engines.

 

I am a little suspect of the injector O-rings as I did turn them a little when I pulled the intake off, but all of the threads and posts I saw on replacing the O-rings said to not do it so I left them alone. I didn't see any smoke coming from them during my test, and trying to spray them looks nearly impossible with the upper intake in the way. I may need to just pull the intake and replace them just to be sure.

 

before you pull the upper and old used car trick to find a seal a vacuum leak is to spray the intake and injectors with clear lacquer. when it dry it creates a seal hopefully stopping the vacuum leak

 

I think I'm supposed to polish it first!
EDIT: The fitting I broke was for the brake servo, not the SAI. I hadn't had my second coffee when I made the first post. Not sure I want to buy one of those. I think it's time to make something that is a little less absurd.

 

a lot of people have replaced that fitting with a brass ****** fitting from HD

 

Can a leak from that POS fitting cause a 1171/1174 trouble code?

Any ling to the brass fitting from HD?

Thanks!

Andy

 

Holy asterisks! Did you drop an f-bomb or is this site messed up? Oh, I get it - must be the other N-word. The things you can put pasties on. Or stare at when it's cold out. How offensive. Glad to see this site is hosted by people that are willing to put in the time to clean up the internet. Guess we need to use the more acceptable "male ****** fitting."

Is the approach to pop out the fitting, tap the plenum then thread in bushings and a "male ****** fitting?" I would want to pull it off to avoid getting cuttings in the intake. I could do the injector o-rings while I was at it. Anybody know what size to use?
Edit: What the?!? The word describing a ridged stub of pipe that can retain a rubber hose is off limits too? Can I say n1pple? Yes, I can! I can use english here but only if it's intentionally misspelled. Excellent. Let me describe Mark Wahlberg with his shirt off, or Scaramanga from James Bond - N1pple, N1pple, N1pple! Take that sensors!

 

for some reason you cant you the work bar-bed on this site, i dont know what.
yes a lot of people simply tap the manifold for a brass bar-bed fitting, it you load the tap with grease it will bring the shaving out with it.