Need some knowledge from a Ford tech

Cave Dave · Aug 16, 2011

My 99 F350 is throwing OBD code P1151.Symtoms are a "surging" idle once the engine gets warm,other than that it runs great.I've changed the spark plugs and fuel filter and am getting ready to change the O2 sensor next.I'm just wondering if any of you are familer with this code and if I'm on the right track.
Truck is a 99 F350 with a 5.4 and an auto 76,000 miles on it.I've looked at all the wiring and don't see anything loose or rubbed thru.
Thanks for any help,I'm a Toyota guy and this thing is kind of foreign to me.

JOOP · Aug 16, 2011

http://www.obd-codes.com/trouble_codes/ford/p1151.php

Cave Dave · Aug 16, 2011

JOOP said:
http://www.obd-codes.com/trouble_codes/ford/p1151.php

That's the page I got when I Googled it a few days ago,my problem is it is kind of vague as I don't have much experiance with diagnosing OBD stuff.Do you think the O2 sensor would be the next thing to replace?

JOOP · Aug 16, 2011

Cave Dave said:
That's the page I got when I Googled it a few days ago,my problem is it is kind of vague as I don't have much experiance with diagnosing OBD stuff.Do you think the O2 sensor would be the next thing to replace?

Do you have a scanner. Look and see if the O2 is working first. Otherwise you're throwing parts at it.

Cave Dave · Aug 16, 2011

JOOP said:
Do you have a scanner. Look and see if the O2 is working first. Otherwise you're throwing parts at it.

The scanner was how I got the code and looking it up on the internet was how I found the same page you did.When you read the page you found what would you have done?
My point by asking if anyone has experiance with this truck-code was to avoid throwing too many parts at it.I bought the truck with 43,000 miles on it and figured it needed the plugs and fuel filter anyway now that it has 76,000 on it.
Thank you for taking time to Google it,I just wish you or someone else could narrow down what to do as it is kind of vague and lists many things that could be the problem.I was hoping to get some advise from someone that had experiance with this particular issue-truck.

Bodaciouscj7 · Aug 16, 2011

Cave Dave said:
The scanner was how I got the code and looking it up on the internet was how I found the same page you did.When you read the page you found what would you have done?
My point by asking if anyone has experiance with this truck-code was to avoid throwing too many parts at it.I bought the truck with 43,000 miles on it and figured it needed the plugs and fuel filter anyway now that it has 76,000 on it.
Thank you for taking time to Google it,I just wish you or someone else could narrow down what to do as it is kind of vague and lists many things that could be the problem.I was hoping to get some advise from someone that had experiance with this particular issue-truck.

As Joop said, if you have a "scanner" you can watch in real time what the o2 sensor is doing. You need this kind of information if you want to properly diagnose whats going on to properly execute the repair.

If you have a code reader, sell it and buy a scanner or find a friend that has one you can use. :awesomework:

Cave Dave · Aug 16, 2011

Bodaciouscj7 said:
As Joop said, if you have a "scanner" you can watch in real time what the o2 sensor is doing. You need this kind of information if you want to properly diagnose whats going on to properly execute the repair.

If you have a code reader, sell it and buy a scanner or find a friend that has one you can use. :awesomework:

I'm embarased now, but it should show my lack of experiance with "new" style cars and trucks. I barrowed a Cen-tech model 99722 code scanner and it told me I had code P1151. I looked it up on Google a few days ago and found the same page JOOP linked but it was kind of confuseing and vague to me.I don't know how to watch in real time what the sensor is doing and I thought I'd ask if there was anyone on this forum that had any experiance with this truck-engine code.

Bodaciouscj7 · Aug 16, 2011

Just looked up that scanner. Website says it will give O2 data.

Does this truck have a 5.4l in it.

Bodaciouscj7 · Aug 16, 2011

Site, unseen, if I had to take a guess to what is going on, my past experience with the Ford mod motors would say vacuum leak.

Check all the vacuum lines around the throttle body, especially the 90 connectors that connect large plastic vacuum lines to the body. That seems to be the most common failure I have to repair on those engines.

Cave Dave · Aug 17, 2011

Yes it has a 5.4L. Thank you for the vacuum leak idea,I'll check it in the morning.:beer:

ain'tstuckjustresting · Aug 17, 2011

How dirty is the throttle plate? I've fixed some pretty random issues with a toothbrush and carb cleaner. It burns a bit but my teeth and intake are shiny. :redneck:

skinny_pedal · Aug 17, 2011

ain'tstuckjustresting said:
How dirty is the throttle plate? I've fixed some pretty random issues with a toothbrush and carb cleaner. It burns a bit but my teeth and intake are shiny. :redneck:

Fords say right on them do not clean. They'll do even weirder sh*t when you do. I would say with that code and syntom to try and clean the IAC and MAF

zukkev · Aug 17, 2011

skinny_pedal said:
Fords say right on them do not clean. They'll do even weirder sh*t when you do. I would say with that code and syntom to try and clean the IAC and MAF

Use the right THROTTLE BODY CLEANER, and there will be no ill effects of cleaning the t-body...just reset the KAM (Keep Alive Memory), and follow the relearn procedure after that...not difficult.