Codes P0327, P0171, and P0174. HELP!!!!!!!

Okay guys I'm back with the same problem. Here is what I have done since Aug. 2008 I have replaced the MAF sensor, air filter, knock sensor, fuel pump, coil, tps, fuel filter, distributor cap and rotor. But guess what I am still having the same codes in this order P0327,P0171, and P0174. I am going crazy. Now what do I do?????????????????????????

As an educated guess, you have a vacuum leak somewhere. Could be the intake manifold gasket or just a worn out tube or hose.

Uh sorry to say but no vacuum leaks. Ran a smoke test and found no leaks.

I forgot, what kind of vehicle do you have?

I have a 1999 chevy silverado 1500 4.3 L. Automatic.

In that case, my next step will be to check the wiring, like plug connections and continuity from one end to the other. I found a common problem with GMs about the cables around 2000 models. For some reason, the copper comes brittle and breaks at the edge of the connectors. One way to find out if that is the case is with a scanner that can read the sensors readings while the engine is running and wiggle the harness and cables around, see if there is a change.

This type of scanners they are not that expensive, I paid around $275 for mine in Auto Zone. They are others that can do way more but I think it was an overkill for what I want it. So I bought the 2nd best from the hand held scanners. The cheapest one only read codes.

I hope this helps

Well ok I have checked all the connectors and still having the same problem. When I had my cousin look at the truck with a scan tool that has a complete readout it showed my timing to be at -13. How to I fix this and if was that for out of time wouldn't the CEL stay on all the time?

you need to retime the distributor which will probably require the scantool! which I think somebody suggestted you check months ago! Alot of them get knocked out of sync when the intakes are removed to fix the leaking gaskets!

Well guys I live in the Houston area. I was wondering if anybody knew of anyone that can adjust my timing with a scantool in the Houston area? I don't know anyone that can do it.

If your buddy has a scan tool with data that is all you need. Are you looking at the cam retard pid or the timing pid? The timing is non adjustable the only thing you can adjust with the dist. is the cam retard degree. This has to do with the cam/crank sync or correlation. I have seen alot worse than -13 degress and not cause lean codes, only misfires codes. Most V6 dist. or not adjustable any way the hold down is made on the dist. yours may be different. Since you have data what are the short term and long term fuel trim numbers? Is this motor stock? No K&N air intake? While watching data look at the calulated load % and take it down the road and floor it and see how high the % goes and let me know.

Hey guys I ran a smoke test again to check for vacuum leaks. I noticed this time that smoke was coming from under where the distributor cap sets at the top of the distributor shaft. Is this normal?

Smoke is probably going through the pcv valve and or the breather tube and filling up the crankcase. If you block them off and do it again and smoke still comes from there then sounds like your intake gaskets are leaking from the underside.

If this is the case could this be my whole problem?

Yea but if this is then it should smoke and probably spark knock. One way to tell is too block off the PCV system and remove the dipstick and rigg up a vacuum guage to the dipstick tube and if you have vacuum on it then there you go.

Ok I used a vacuum gauge on the dipstick and there was no vacuum. But what would cause the CEL to come on for few hundred miles and be off for a few hundred miles? I know if I had an vacuum leak, exhaust leak, and or an intake leak wouldn't the the CEL be on all the time?