OK, let me start with I'm one step away from getting rid of this car while it still runs. I truly don't want too but it's driving me nut's!!

For a little history see my original thread "Another P0171 Lean Code Issue -FIXED"

After the smoke test, the leaking vacuum ports were fixed, the leak at the throttle body was not (told the entire unit would need to be replaced). Car ran great for a few days so I reported that it was "fixed". Nope, I spoke too soon. A day or 2 latter I popped the P0171 code again, and again, and again. Next project was to do a complete gasket change per the recommendations from here. While I was at it I inspected (again) every hose, vacuum connection and vacuum tube with no faults found. All plugs were changed, all gaskets (upper & lower manifold, and TB) were replaced. During this process I discovered a couple of things that may or may not be related. The bolt on the passenger side to the upper manifold was/is completely stripped out (in front of the IMT valves) and the bolt on the back of the manifold was missing (still is, my baseball mitts won't fit back there). The car ran GREAT for 2 days then.......it happened again! It has now thrown the code at least once per day for the last 3 day's. I'm at a complete loss as to what to do next?

Is it possible that the stripped and missing bolts are creating a small vacuum leak (there was none discovered with the smoke test)? After the smoke test the leak that was not repaired was at the "throttle sensor o-ring". Can this area be covered with tape/RTV or silicone? Seems absurd that I would have to replace the entire unit for a faulty o-ring but it is an X-type.

I'm open to what needs to be done next. Please help!

 

water, unfortunately, from what you are describing, your issue is the throttlebody. now, depending on how comfortable you are with doing some work yourself, you should be able to dismantle the throttlebody some and replace the worn out o-ring. Make sure to look really closely at the inside shaft to make sure that it is nice and smooth and has no burrs on it (these will cause the o-ring to fail rapidly). You should be able to pick up a new o-ring at the auto parts store (general use bins, take in the old one to match it up.

Unfortunately, you are looking at having to drain out part of the coolant to do this work and exactly what needs to be done I can't give you a specific answer on. I know you will need to remove both the throttle position sensor and the actuator motor (left and right sides of the throttle body). Then you will have to remove the 2 screws holding the butterfly plate in place. From there, you should be able to slide the shaft out and access the o-ring(s). Since you are in there, I would recommend doing a complete o-ring change out. A few more dollars, but then you will know beyond a shadow of a doubt that the throttlebody is no longer the issue. Since you have it torn apart this far, a good cleaning of the throttlebody will be easy to do too. Make sure to get the thin edge of the butterfly plate as gunk forms there and can easily lead to problems in the future.

 

Well I took the TB out this weekend and was unable to find any tools to remove the sides to be able to do the o-ring replacement. I went to the web and found a used TB for $450 with a warranty so I'm going that route. Any other suggestions if this is not the fix? Someone in my original post mentioned the brake booster itself may need to be replaced? How in the world do you check if it is bad?

 

waterfowlhntr, I would simply remove the brake booster hose and plug that with the car idling. You will need to clear the codes first, but if the check engine light comes back on, then you know it isn't the brake booster. If the light remains out after 15 minutes or so of idling, then you can rest fairly comfortably that the problem is the brake booster. But, if the light comes back, you know it is something else.