I have a 00 rwd v10 X, recently we did an engine swap. The "new" engine came of 01 X with lower mileage we put new timing sprockets, tensioners, chains, seals, and gaskets. We put new 02 censors new coils, plugs, and fuel filter. The motor sounds fine but its shaking a bit, when i put my foot on the gas it goes but it feels like it has little power and its got the P0171 and P0174 codes on. One guy told me it could be that the timing is off and another guy said my fuel is dirty and it needs the tank cleaned. Anyone help me? your help will be much appreciated

 

Those are lean O2 sensors bank 1 and bank 2.

Do you have exhaust hooked up?
Are O2 sensors hooked up?

 

yeah everything is hooked up, i just want to know why is it low on power and why the codes.

 

Could be a vacuum leak adding air that MAF does not log. Check IAC, and all vacuum lines.
Make sure MAF is hooked up. If upper throttle body plenum was replaced make sure there is no vacuum leak at gasket. Make sure the lower intake is not cracked, causing a vacuum leak.....it's plastic.

Motor is "seeing" more air than its being told is there. So codes says O2 sensors are reading lean, duE to too much air.

I suppose both O2 sensors could be bad if they got squirted with pb blaster or something, ma king them read wrong.

Could be bad injectors, but I suspect too much air causing too much oxegen in exhaust.

 

ill take a look at those things and let you know

 

Also check the air tube between the MAF and the throttle body.

 

Moved over to the V10 6.8L forum for you.

Stewart

 

Thank you