It well may be the plenum issue. I have read about it extensively, but I wasn't going to do anything until it started going through coolant or oil, or started running poorly. The yellow engine light has gone on and off since I first bought the truck 60k miles ago. And after I finally got around to getting it checked, I thought it might be the plenum. Like I said, though, I'm not going to worry or do anything until it starts causing problems. When I keep my speed at a maximum 65mph, I get 17 mpg consistently. If I keep it between 45-55mph(Boy I **** a lot of people off in the 65mph zones-which is most of the roads around here), I get a consistent 20 mpg. That's why I have let the ABS and misfire issue alone. If it ain't broken-I don't want to screw with my mileage and change anything.

 

Waiting for a problem with these things is when it's usually too late(and you have the #5 misfire). At the very least I'd start by getting a PCV valve from the dealer. And that's awful good mileage. You going by the overhead by any chance?

 

It only has the temperature outside. No, I'm going fillup to fillup and I still have the factory wheels and tire size. I really, really drive like a grandma, no poop! I take off slowly and brake well ahead and I've been keeping right at 50 mph on the open highway. If I drive normally, I get around 16mpg. So, with the platinum plugs, wires and granny driving, I have came up with a system that works. Now ask me what I got when I towed a 13k # mobile home. I barely got 8 mpg.

 

If the cruise powers up, check the vacuum line to the module. Module is under the battery. Make sure it hasn't been eaten by battery drippings.....

 

Thanks, I'll check that. My posts and clamps were corroding terribly.

 

If you wait until you are going through cooland and oil, you may want to go ahead and order a set of heads to replace the ones you are going to crack.


And driving 20 mph under the speed limit is terribly unsafe. I hope mpg is worthe the livesnyou may be putting at risk.


If the plenum is bad, it is already "broke."

 

It is worth the gas I save. Hell, this is Arizona, half the geezers drive like this already-people are used to it. I was never an engine specialist, but I did rebuild a few when I was still a Ford/GM/Toyota/Nissan tech, but I maintain and watch all fluids religiously, several times a week. Long before it reaches the point of endangering the engine, I would notice oil and/or coolant usage. But I do appreciate your concern.

 

I went ahead and replaced the brake switch. I've done several before and this was the hardest I've done. I'm 6'5" and even with the seat all the way back, there's still just too little room for me to get up under there. Anyway, the ABS/speed sensor is replaced, the brake switch is replaced and I found out the vacuum line was broken off from dry rot at the bend where it plugs into the servo. So, with the vacuum line replaced, everything is working. I appreciate the assistance.

 

Awesome, glad you got it figured out. And thanks for letting us know.

 

in New york if your driving 45 in a 65 you ned to have your hazard lights on or you get ticketed... since those "geezers" often cause so many accidents that way.