Ok, the other night my truck threw the ses light. Went to Autozone, they told me these two codes popped up. First, i cleaned my MAS, had the light cleared, it came back on. Next, i bought a new MAS and replaced it, had the code cleared, it popped back on. Now, the truck idles rough on occasion, and stalls at red lights on occasion. It started sucking a lot more gas right when the light came on. Pretty sure it's a vacuum leak, but can't find it as of yet. Any help where i should check? PCV? Not sure exactly where that is located. I am assuming it is in the valve cover? This is a 4.6 liter, 2002. Only mod i have is an Airaid intake. Trying to avoid the 85 dollar dealer diagnostic fee...

Any help guys?
Thanks!

 

Your going about it right , I think - I assume you mean MAF not MAS , because I dunno what that is on a 02 lol . Look at this elbow for sure (back by the firewall) - It's the biggest leaker -




After you've gone thru the vac lines , the next thing to check is your manifold gasket..

 

Yea, meant MAF not Mas.. sorry, old habit from my Trans Am days...
Does that tie into the top of the intake or near the bottom?

 

Yup -MassAirFlow Sensor (MAF) @ towards the bottom - IntakeAirTemperature Sensor(IAT) @ towards the top

 

OK, show of (bruised and bloodied) hands of those who have swapped out the pcv tubing. It took me almost 2 hours to get the boot off the back! It ripped when i was taking it off and the remaining part was fused to the intake from all the heat! Almost decided to take the throttle body off all together to get to it. Idle is back normal now, just need to reset the light and cross fingers it worked.

 

Oh yeah , your not suppose to take those off

Just Kidding

It was stuck on there pretty good huh, that stinks , could you tell if it was leaking before it ripped ?

 

HA HA!
I tried feeling back to the elbow, it felt really squishy, and i think there was a tear in it, not positive. It was definitly shredded when i got it all the way off. It doesn't stall so far, and it idles smooth. I just hope that was my problem. Don't think i have the time to replace the intake manifold if that is my problem, at least this week. Besides, that looks like a nightmare in itself...

 

You most likely fixed it. That elbow is a real POS and causes this fault more than all the other causes put together.

Steve

 

When i went to the dealership to get the part yesterday, there were two parts for the same year motor out of the same plant. Had to match them up outside. Then, i was talking to a tech guy about the codes i got and what my plan was, of course his response was, No, you are way better off to come in and let us diagnose it for you. You are just going to wind up throwing money at trying to guess. Yeah, well, i'll gamble this 25 bucks versues your 85 dollar diagnostic fee right now. I have a friend who is a mechaniac at the same dealership, he is on vacation this week. Talked to him, he said i was definitly on the right track, the pcv tubing is very suspect on these trucks.
Hope this works, my knuckles can't take much more abuse

 

Well it sounds like you already came to the right place

 

yeah, wish i was near my computer this weekend when it all started. At least i can take back the MAF sensor and get my money back for that.

Thanks for all the help so far guys!

 

Another quick question.. what is the tube that plugs into the top of the intake, looking at the engine from the front, on the top right hand side in the back? It comes from a distrubution block on the fire wall. My tube was cracked, but had no holes... looks like it might need to be replaced at some point.

 

That your IAC tube - that has everything to do with the way it idles and runs..

 

I'll take another look at it tonight. It was kinda cracked, but not all the way thru. I just had my t.b. cleaned of all the carbon buildup about 10 months ago, i pulled another code of insufficent egr flow. My iac valve should be ok, but might not be bad idea to check it as well.

 

you have that code now?