Well, I broke down and put a hughes plate on my truck. Wasn't a lot of oil in the intake for a truck just shy of 150k, but the gasket was poking out the sides in a few places when I flipped the manifold. Hughes kit came with an odd gasket. Victor Rienes brand. The plenum gasket was all metal (steel I guess), with a raised edge that I suppose crushes when torqued down. I'm a bit leary of it (kinda makes you start to think about the whole steel vs alum expansion rate thing), but hopefully it'll be ok. So far, I've noticed it seems to idle a bit smoother. Did not do seafoam yet, but plan to and then install front 02 sensor. At this point do I need to try and reset the pcm, or did it reset on its on? I had the negative battery cable off since about 8:30 thursday night. Started working on it then and finished up this afternoon.

 

It should have reset on its own. That sounds like plenty of time to me for what little charge is left in the computer to drain on its own without having to turn on the headlights or anything.

She'll get slightly worse MPGs and power for a few dozen to a few hundred miles as the PCM relearns the sensors. Install that front O2 ASAP, so it can learn the readings from a new, fresh sensor instead of the old, possibly ruined by bad plenum unit.

 

And disconnect the neg cable again before you change the o2.

 

I just did the same thing (plenum fix)
Had the negative off for about 10 hrs. Do I need to reset the comp?
I also changed the front o2 a while back and did not disco the negative.
Should I have?

And yes, jswain, it feels great to have that dadgum plenum in the past.

 

Ten hours of disconnect will have done that for you. No worries there, keep on truckin'.

 

Well, driven the truck about 120 miles since the plenum (damn, said it again) repair and new 02 sensor. Not much change in performance, haven't noticed any oil loss but I wasn't burning that much oil before (one quart/1500 miles). I have however encountered some pinging...which I did not have before. So, I guess I need to look at my plug wire routing again? Maybe the new 02 sensor is making the engine run a bit leaner? Or lastly I did something wrong on the plenum repair. If its that last one I'm gonna break something. Do you yall think the pcm has adjusted to the new 02 sensor and plenum repair yet? I did reset pcm when I put it on. If all else fails I'll try the old 02 sensor again.

 

Plug wires rerouted. Still pings a bit under heavy throttle. I don't know that it pings enough that it would even bother a normal person. But I, like most on this forum I assume, am pretty particular about my vehicles. So does anybody know how long it takes the pcm to adjust to plenum repair and new 02 sensor? I'd think it would adjust pretty much instantly?

 

Keep us posted on the metal gasket, I did my plenum awhile back, opting to use an upgraded gasket instead, and low and behold, it needs to be done again. This time I'm thinking of seeing if the all metal one works. Did you use any gasket sealer? or just installed it dry? 120 miles...maybe, it depends on how many times its run in that 120 miles I believe, ( run time cycles??) give alittle more time.

 

Have driven it over 300 miles. Seems ok, not burning any oil. Haven't noticed pinging again, but it only does it if you really romp on it, and I drove pretty easy on that tank of gas to see if I could get better mileage. I didn't, I guess 13 mpg is about as good as I'm gonna get. I didn't use any sealer, was told by an engineer friend not to use rtv on the metal gasket. How do you know yours is blown again? Is it an aluminum pan?

 

Mine pinged until I ran Seafoam through it. Cleared it right up.