Dang Codes!

bassadict69 · November 19, 2008

My truck spit & sputtered while driving a little this morning & the SES light came on. I took it & had the codes scanned & it showed p0171 & p0172. I have searched some here & will try cleaning my MAF this evening. I changed the pcv earlier but it did not help.

I does seem to miss & stutter more when cold. What is the easiest way for me to check the intake for a vacuum leak? Can I do it without a scanner?

alwcurlz · November 19, 2008

My truck spit & sputtered while driving a little this morning & the SES light came on. I took it & had the codes scanned & it showed p0171 & p0172. I have searched some here & will try cleaning my MAF this evening. I changed the pcv earlier but it did not help.

I does seem to miss & stutter more when cold. What is the easiest way for me to check the intake for a vacuum leak? Can I do it without a scanner?

What kind of truck is it? Year? Engine type? Miles?

Does it go away after the engine warms up, or is it sputtering/missing all the time?

I'm not sure if cleaning the MAF can be done but, a replacement runs about $70-$80.

bassadict69 · November 20, 2008

Check my sig...it is a 2002 Silvy 4x4 with a little over 100,000 miles on the 4.8

When cold, it does it REAL bad. Once it warms up, it does it off & on while driving. It is just a kind of hard miss that drops the rpm's enough that it kind of jerks the truck! I also noticed on the way home while sitting at a red light, that the rpm's would surge up rocking the truck forward if I didn't have my foot on the brake hard. The SES has not come back on yet.

I pulled the MAF & cleaned it with some MAF cleaner...it did not look dirty but I did it anyway. Pretty sure that did not work but I will find out for sure tomorrow.

alwcurlz · November 20, 2008

Check my sig...it is a 2002 Silvy 4x4 with a little over 100,000 miles on the 4.8

When cold, it does it REAL bad. Once it warms up, it does it off & on while driving. It is just a kind of hard miss that drops the rpm's enough that it kind of jerks the truck! I also noticed on the way home while sitting at a red light, that the rpm's would surge up rocking the truck forward if I didn't have my foot on the brake hard. The SES has not come back on yet.

I pulled the MAF & cleaned it with some MAF cleaner...it did not look dirty but I did it anyway. Pretty sure that did not work but I will find out for sure tomorrow.

Ok, same GMT as mine. After I cleaned my throttle body because of the sludge buildup, the truck ran awful but, ran fine after a day. I didn't clean the MAF.

bassadict69 · November 20, 2008

Thanks! I may have to try cleaning the throttle body first before doing anything else.

Anything I need to be careful NOT to do when cleaning the TB? Is it ok for the TB cleaner to get down in the Tb & take some of that gunk with it? I have never tore into something like that so I do not want to make matters worse!

bassadict69 · November 20, 2008

Well. seeing as how my truck is now sitting on the side of the road broken down, I am reckoning the problem was not the MAF sensor I cleaned last night.

This morning, I left the house & I could just barely feel a miss or a sluggish feeling. A couple of miles later it got worse & I could not get the truck above 45mph. Within a mile, it was spitting & sputtering then died! I got it off the road, let it sit & tried to crank it...it would barely start, idle REAL rough for 5-10 seconds then bite the dust again.

Would a weak fuel pump cause the codes I got yesterday? The SES light did come back on this morning & everyone seems to be thinking it is a fuel pump problem.

HELP...I NEED YOUR IDEAS ON THIS!

Draenor · November 20, 2008

Have you checked the fuel pressure? or changed the fuel filter?

bassadict69 · November 20, 2008

I am waiting on a mechanic to come get my key...he is going to go out to the truck & check the fuel pressure for me. It will probably be later this afternoon before he gets out there though.

Fuel filter is about a year & half old, if even that old.

Draenor · November 20, 2008

Fuel filter is about a year & half old, if even that old.

You'd be surprised what can get cought in there in that amount of time.

pennzoil29 · November 20, 2008

Fuel filter is about a year & half old, if even that old.

You'd be surprised what can get cought in there in that amount of time.

A year and a half, damn, I change mine twice a year.

alwcurlz · November 20, 2008

Well. seeing as how my truck is now sitting on the side of the road broken down, I am reckoning the problem was not the MAF sensor I cleaned last night.

This morning, I left the house & I could just barely feel a miss or a sluggish feeling. A couple of miles later it got worse & I could not get the truck above 45mph. Within a mile, it was spitting & sputtering then died! I got it off the road, let it sit & tried to crank it...it would barely start, idle REAL rough for 5-10 seconds then bite the dust again.

Would a weak fuel pump cause the codes I got yesterday? The SES light did come back on this morning & everyone seems to be thinking it is a fuel pump problem.

HELP...I NEED YOUR IDEAS ON THIS!

Yeah, work your way back is one way to find the problem. You probably have it figured out now, considering the fuel filter and fuel pump. Depending on how much driving you do, the fuel filter is one bet you can take.

bassadict69 · November 21, 2008

I did not realize that the fuel filter needed changing so often...I will be sure to change it now.

My mechanic went out today to check the fuel pressure & said it had ZERO pressure & that it was definately the pump. Sure hope he is right since I will shell out almost $300 tomorrow for the pump & spend Saturday trying to figure out how to swap it out...I will be learning this one by trial & error!

alwcurlz · November 21, 2008

I did not realize that the fuel filter needed changing so often...I will be sure to change it now.

My mechanic went out today to check the fuel pressure & said it had ZERO pressure & that it was definately the pump. Sure hope he is right since I will shell out almost $300 tomorrow for the pump & spend Saturday trying to figure out how to swap it out...I will be learning this one by trial & error!

I would change the filter first, before tearing into the fuel pump! Fuel pumps last longer than 100,000 miles.

alwcurlz · November 21, 2008

I did not realize that the fuel filter needed changing so often...I will be sure to change it now.

My mechanic went out today to check the fuel pressure & said it had ZERO pressure & that it was definately the pump. Sure hope he is right since I will shell out almost $300 tomorrow for the pump & spend Saturday trying to figure out how to swap it out...I will be learning this one by trial & error!

I would change the filter first, before tearing into the fuel pump! Fuel pumps last longer than 100,000 miles.

BTW, did your mechanic say the pump was bad because of the lack of fuel pressure, or because the fuel pump does not run?

Draenor · November 21, 2008

I did not realize that the fuel filter needed changing so often...I will be sure to change it now.

My mechanic went out today to check the fuel pressure & said it had ZERO pressure & that it was definately the pump. Sure hope he is right since I will shell out almost $300 tomorrow for the pump & spend Saturday trying to figure out how to swap it out...I will be learning this one by trial & error!

I would change the filter first, before tearing into the fuel pump! Fuel pumps last longer than 100,000 miles.

BTW, did your mechanic say the pump was bad because of the lack of fuel pressure, or because the fuel pump does not run?