Engine light coming on for awhile and then going off for awhile.

[j cAT]

Originally Posted by robertbassin5

I have already ran all the checks for the knock sensor and they were ok.

the only way to check the KS without any doubt is to use the oscilliscope.... this will show the high speed dropouts that a bad KS can produce,, that a meter will never see /read,, and this is one way to troubleshoot intermittent problems ....the reason I did not mention this is,, most vehicle owners on this forum don't own a tool such as this...


this is why I suggested the replacing of this part....your dtc is saying that it has lost a signal...from it..

[robertbassin5]

I wondering if changing the negative wire from the battery would help?

[robertbassin5]

Well guys after really looking over my truck I noticed 2 things. 1st was the negative wire off the battery to ground was in bad shape (wire was replaced) and 2nd the o2 sensor connector on the passenger side had some corrison on it so I cleaned it with electrical contact cleaner. Started motor and within 1 min. the light turned off. Keep your fingers crossed. I will let you guys know.

[robertbassin5]

Well the light came back on!!!!!!!!!!!!!!!!!!!!!

[robertbassin5]

Well guys the light came back on again with 3 codes now and they are p0174, p0171, and p0327. I know what these codes are cause I have checked all the possible causes for them and there is nothing wrong. I am lost.

[MT-2500]

System running lean on both banks,
Could be many things.
MAF sensor dirty.
Air leak in intake air.
02 sensors bad.
Or even fuel pressure low.

Start with a good fuel pressure check.
Check and clean MAF sensor for starters.

Get some good repair info and go threw the repair flow charts for the codes.
http://www.alldata.com/products/diy/index.html

MT
MT

[robertbassin5]

Everything you are requesting to get check have been already checked and passed.

[MT-2500]

Have you went threw the repair flow chart for the codes?

[robertbassin5]

My cuz works at Firestone and he ran all the checks ( Smoke test, fuel pressure check). The scanner my cuz has at Firestone shows exactly what happened when the light came on. The only thing I can remember that he found was low voltage in vacuum.

[j cAT]

Originally Posted by robertbassin5

My cuz works at Firestone and he ran all the checks ( Smoke test, fuel pressure check). The scanner my cuz has at Firestone shows exactly what happened when the light came on. The only thing I can remember that he found was low voltage in vacuum.

the problem with this extensive post repair is the fact that you do not give detailed readings....cuz checked this and that... next post start talking some figures and specs... maybe the cuz don't know these things....


if the scanner showed what caused the light to come on ,, why is it he can't give detailed info....????? or repair this minor issue????

[robertbassin5]

Because everywhere I have taken it everybody is puzzled. Cause when there is no vacuum leaks, fuel pressure 59 to 60 psi.,MAF sensor new, and the O2 sensors were changed last December. Like I said all these problems started after the engine was replaced and the reason it was replaced cause it spun a rear main bearing. Is this enough info?

[Scrapper]

you don't by chance have a k & n air filter in it do you? if so theres yor ploblem you can get to much of the red grease on it will mess up your maf and your 0-2's..and if your thinking if you take 0-2 sensor and cleaning them your wasting your time.

[robertbassin5]

No I don't have an K & N air on my truck. To be honest I wouldn't on my truck period.

[MT-2500]

Originally Posted by robertbassin5

Because everywhere I have taken it everybody is puzzled. Cause when there is no vacuum leaks, fuel pressure 59 to 60 psi.,MAF sensor new, and the O2 sensors were changed last December. Like I said all these problems started after the engine was replaced and the reason it was replaced cause it spun a rear main bearing. Is this enough info?

As J-cat says wen need info.
Fuel pressure 59 -60 may be one problem.
Specs is 60/66 lbs of fuel pressure.
A good engine capable scanner will point you to the problem.
But you need someone trained in engine running problems and someone that can read out a scanner and.
Good repair info is your best friend.


When looking for a good repair shop.
Check around Ask around
Word of mouth.
Family friends coworkers neighbors business people and delivery people.
Mailmen and parcel delivery people get around and notice a lot of stuff.
Even a good parts house knows what shops are good and not good.
Chamber of commerce and better business bureau and city hall.
If you find a good referral to a repair shop go look them over and talk to them.
Look for a clean looking busy place with nice people running it.
Ask a few questions and ask about their qualifications and training.
Not all places have trained tech/mechanics.
If they do not find a place that does.
Even all dealers do not have all trained techs/mechanics.
MT

[robertbassin5]

I really appreciate all the help. But the only thing stopping me from having a professional looking at it is $$$$$$$$$$. My money tree is empty.