I have a 2000 F150 Supercab XLT, 4.6 automatic. A couple of months ago my check engine light came on, I had Autozone read the codes. They said maf malfunction. Read here to try cleaning with maf cleaner. Cleaned and reset lamp. Drove good for a few weeks then started running rough and check engine light comes on. Back to Autozone, this time egr is ineffective. Read the forumm about cleaning intake and egr ports. Took it apart, sure enough ports are almost completely blocked. Cleaned every thing and reset the light. Runs good for about 20 miles and then starts missing and check engine light. Back to Autozone, this time I get the code P1151. Read through post and decide to replace drivers side upstream o2 sensor. Also changed fuel filter at this time. Reset the light and took for a test drive. Initially seemed good but the farther I drove the I still had a miss at 35 to 40 at steady acceleration. Smoothes out at cruising speed but misses under a load ( like going up a hill). Proably 75 miles and 12 on/off driving cycles. There is no check engine light on now. Any ideas are appreciated. This forum is full of so much great info and helpfull people.
Bob

 

Do you have a hand held vacuum pump? If so Hook it directly to the EGR and see if you can get it to cut out. But keep the vacuum under 10lb, so s not to damage the valve itself.
If a pump is not available, hook a pice of tubing to the egr and suck test it.
The engine should cut out when you apply vacuum.
Report your results and someone will get back to you.

 

Hi & welcome.

I have little idea, but I sure know who does. I'll page him for you...



Meanwhile - it would help some if you could post maintenance history. Plugs/Cops/boots, Mileage on truck, any mods, etc, etc.

Check for vacuum leaks, etc.

Also - random lean misfires can set pending codes not readable by Autozone's simplistic scan tools. You'd need a good shop (or dealer) to pull those - and it's gonna cost.

Gather/post info and wait fer Jbrew. He'll nail this, as he usually does.

Good luck!


MGD

 

Thanks for the quick responses. Mileage 154,494 currently. Had the Ford dealership replace 3 cops about 4 years(60,000 mi. ago) they then replaced 2 more a year later. I found this forum and needed to replace a bad one and followed instructions here and replaced another one last year. When my most recent problems started I figured I had problems with the cops but scans indicated other things. I'll try vacuum testing the egr valve later today. Thanks again for the help. Bob

 

When was the last time the plugs were changed, and what brand are they?

 

Well, today on my way to a job the check engine light came on. I bought a scan tool from Autozone and checked it out. The code was p0155. Indicates drivers side front o2 sensor. Since I just replaced it, I checked the forum for code p0155 and it seems the next step is to check harness/connector. When I changed the sensor, I looked at the part of the harness I could see. It seemed fine but could see only a little of it. The connector was in good shape with pins solidly in place, no corrosion. Haven't been by to get vacuum line to test egr.
Thanks again for advice and suggestions. Still hoping to avoid taking to the dealership.
Bob

 

Guess he doesn't want to answer that one, I've been waiting for it. Oh well.

I'm not gonna ask any lol. Nothing worse than someone who won't work with yuh, - when your trying to help them. Doesn't make sense.

Yea, sorry MGD and thanks for the compliment.

 

NP bud - you amply deserve it

C'mon now, Bob. I asked you, GLC asked you, so you need to supply info on the status of yer sparkplugs to move on with this.

Okay?

Please don't squander Jbrew's expertise. If you continue to put in the effort, so will he. I've seen it many times - it's like a dog with a t-bone - won't let go 'till it's done & buried (okay - bad analogy, but you get the picture, ).


MGD

 

Sorry Guys, i just got back into town. My Father passed away suddenly and the truck was the last thing on my mind. Thanks for everyones advice but I'm taking it to the dealership tomorrow. Bob

 

Sorry to hear that man, -yea screw the truck. I can sort of relate. My Father passed away unexpected as well, - only three years older than I am now. Sucks, still does.

That's to bad, If yuh still need a hand in the future with the truck, - stop back by ehh.

Good luck man, - Prayers.