Hey all,
My truck is surging while driving at low speeds and idling a bit high... i got two codes that came up p0174 and p0175 ... i thought it might be the TPS now i dont know.[:@]

Thanks for any help

 

anyone?

 

The codes are for bank 1 oxygen sensor lean and bank 2 oxygen sensor rich.

This one's a tricky one. I doubt that both sensors have failed. The first thing to do would be to check your fuel pressure. A bad fuel pressure regulator is the common cause of these two codes showing up at the same time. Fuel pressure should be somewhere around 49 if I remember correctly. Check that out first and let us know what you find.

Also, check and make sure the lines running two/from your gas tank aren't pinched or damaged at all.

 

ok i will check the fuel pressure friday and let you know, thanks for giving me a place to start. also im going to crawl under right now and look at the fuel lines.

 

Ok,where to start.. saturday i took the truck to a buddies house.. he was covinced it was the TPS so we replaced it. Truck still does it. The CEL light turned off before i got to his house but he found one code. p0175. Well i drove it home and waited till monday to take it to a different buddies shop on the way there truck throws the CEL light. Get to the shop he takes it for a test drive to feel what i am describing as a surging and un ability to shift properly. He gets back says sure enough there is a problem... he reads the codes p0152 comes up. So i head out and grab a new o2 sensor.. because he is insiting its whats wrong. we replaced it and now no codes showing up at all but the truck is still doing it!!!![:'(]

I asked him to check the fuel pressure before i left and he assured me it was nothing to do with the fuel pressure.. but i insisted CHECK the fuel Pressure... so we did and it came up 48.5 psi on the first check and about 10 min later we checked again after the truck had been sitting and it was the exact same 48.5 to which he then said "told ya so. "

So this is where i am at... The truck seems now to be starting in 2nd gear sometimes, is the tranny just giving up the ghost? it surges a bit at mid throttle.. also feels like a dead spot in the throttle(mid way as well) and when you let off the throttle it seems to make it go faster (only sometimes). Does the same things in OD or od/off. oh also in gear it wants to idle about 1100 rpm with my foot off the brake.. it will go down to about 700 with my foot on the brake but it seems like its pushing the truck.

Any ideas? i read on another forum something about a governer something or other in the tranny?

Thanks for you help! sorry for the longer post but i am getting frustrated and i want to give as much info as i can.

 

**tuesday the saga continues**
truck is now throwing a p0175 again.. what could make it run rich beyond the o2s? could it be the spark plugs? i have not done them since i have had the truck? - i am willing to throw money at the truck i just wish i knew where to throw it.

Thanks

 

i doubt its the problem, however i had problems with my truck surging and my problem was my iac. My truck surged so bad that at one point when i had bald tires and it was raining , while i was on the highway doing about 70 my tires would actually spin when it surged. I then checked the tps, map, and iac at the same time. I noticed that my wiring harness for the iac was loose, so i tightened it. I then cleaned the iac, map and tps off with some throttle body cleaner. Never had a problem again.

 

*update*


Well i replaced the plugs. cleaned the throttle body, cleaned then replaced the IAC as it was trying to srping apart. Also well test driving it i was out on a dirt road and it started raining quite hard. I tryed sticking it in 4/hi and the light did not come on signaling to me a vacuum leak in the CAD... found the leak it was a steel line i replaced that. Truck seems to do alot better shifting, but the high idle condition remains. And i keep getting a p0175 (system running to rich).

While cleaning the throttle body i noticed a Green vacuum line (behind the throttle body near the firewall on the drivers side) with what apears to be a one way check valve. Its not connected to anything... and i cannot seem to find where it goes. its ran in a loom with a grey vacuum line that goes around to the passenger side.

I dont know what to do next i have had a mirror in there and i cant find where it goes. I dont know if this could be adding to my running rich high idle condtions. but i imagine its not good.

any ideas or suggestions welcome.

 

i dont know off hand what that line is but if you give me the last eight of your vin i may be able to find a good vac diagram for ya

 

Hey cool, thanks. The last 8 are WJ238530.