I've noticed recently here after some upkeep on my truck, that my power is just going to crap. I got about 160k miles on my 302, but it shouldn't be crappy in 5th gear when it wasn't before.

I change oil regularly, and keep good fuel in.

I got new IAC, new TPS, Fairly new plugs and cap/rotor.

Everything is in order from what I can tell. I pulled all the plugs, and they are all the same color, and fireing well. The rotor cap and Distributor cap look great. I touched the surface of the rotor cap up to rough it up for better spark again, something I do.

Exhast is good. drive train is good. Changed oil in my Transmission. New rear end bearings, new driveshaft u-joints. T-case was rebuilt a while back.
Damn near a new drivetrain.

I threw some sea foam in the oil this time, to see if I had some sticky rings, or any other things.
Injectors seem to be good, and FPR is the only thing I havn't replaced, but has none of the normal signs of being bad.

I have some cleaner in the antifreeze, and the cooling system is running a little warmer now, which I can't figure out. I think the sensor got cleaned off, and is reading more accurate now.

I have no other idea's here. It just feels so sluggish, especially in 5th gear.

Anyone have more ideas?
I'm missing my O2 sensor, thats it. But I don't thing that would cause this much problem, and my emmissions return was cut off, and dosn't seem to function, but the truck ran better before. So, those arn't the problems.

I've changed all the other parts, and done the other things chaseing down my sudden drop in fuel mileage, and it hasn't helped the power either.

 

i should have this as a permanent reply get some Sea-Foam and follow the instructions.....and dont forget to clean the backs of the butterflies in ur throttle body and the hole to the IAC....shoudl fix ya up.

 

pull the codes.
check the cat, could be plugging
check the air filter

 

Wow. Freefrusty didn't read at all.

New IAC.

I ran seafoam in there that way, and the TB is fine also.

NO cat, and airfilter is fine.

 

guess i did miss that.....i see it says you put it in the oil.....did you try pulling it through your brake booster line though?? thats the way i noticed the most improvment

 

Do you have or have access to a 5gas analyzer?? EEC IV Monitor?? Smoke Machine??

These things will tell you alot.

 

That's definitely a problem, your milage and power will suffer without this piece connected.

 

your truck will run rich w/o your o2 sensor...