REALLY LONG POST SORRY hey guys ive posted a few times before and you all have been very helpful. i was wondering this time if you could give me some advice on whats goin on with my truck. i just got a new trans with PI 2400 torque converter and JDM line mod valve with 4x4 pan put in yesterday by JDM. i checked my scan gauge shortly after i left JDM and took my truck for a drive to wear in the tranny a little bit. after about 30 mins of babying it i put the truck in park and it wanted to stall on me. it was coming to almost stalling out than would rev back up and than do that same thing over and over again. i checked my gauge and two codes came up. P0171 and P0174. i see that these are lean codes and 2 weeks before i put my trans in i threw on a upper intake manifold and a sbtb. i didnt throw any codes until after the tranny was installed. why would this be and what do u guys think the problem is??? any and all info would be very helpful. thanks again. (im thinking i just need an upgraded tune).....?

p.s. my air to fuel before i put the manifold, sbtb and trans in was perfect straight across the board wen i got it dynoed.

 

it could be the pcv hose that connects to the rear of the motor just above the bell housing. you have to pull the blower to fix it.
i just had that code and that what was recommended. i replaced it and it did not fix the problem. it was my fuel pump, one of the hoses ripped in the tank.

 

also if you are around long island i have a spare hose i can sell you.

 

also you might check out your o2 sensor. i dont know if it has anything to do with the leanness but when i put a new one in when my truck was running rich, it solved the problem. just a thought

 

if it was one of those things wouldnt my check engine light come on? it never came on i would havenever known that i had this problem without the scan gauge and the fact that it wants to stall out. i took it for a ride today and it didnt want to stall out it seemed fine. im really confused on what this could be. i think im guna take it over to jdm and have them take a look at it.

 

Those codes come with a long list of possible causes. As far as being related to the tranny install, like halflife said it could be the pcv hose in the back of the block. Could have gotten knudged or something.

I had those codes and it turned out to be my pcv valve. I had a friend with a NGS ford scan tool and we watched the short term fuel trim and sprayed the pcv/vacuum system with carb cleaner while it was running to find a leak. That was my experience.

Keep us posted.

 

well i did install and oil sep on the passenger side and a breather on the driver side about 3 weeks ago. you think that could be it? the computer finally realized im losing pressure due to the breather?

 

the hose in the middle with the green sticker on it is most likely your issue

 

save target as....

don't get to see that view often..if only my hands had eyes

 

ditto!

I haven't been on the boards lately, but was just browsing b/c I was looking for answers to the same issue. I'm running a C&L upper, SBTB, K&N intake, #4 pulley, plugs, 160 T-Stat, FTVB, 4x4 Pan, MAC Cat back, and tune. Ran with no problems for a while and then threw the codes. Took it to the dealer to switch vaccum hoses and they couldn't find a problem. I got a 2% richer tune from my tuner and it stopped the codes for a while but now they're back. I was thinking it could be my fuel pump since it seems to happen when I hit 1/4 of a tank, though that is a theory since I just started watching (happened today).

Any easy way to check if a pump is the problem or if it's the hose behind the s/c?