Had a cel on my 2005 x type for P1647 so I replaced the 02 sensor, drove around some and then did a code check to remove it. It now shows 5 codes so I just deleted them all and the cel goes off and I drive around some with no light coming back on. 1 day later cel is back with P0170 thru P0174 and if I delete the codes before driving the light stays off. car drives fine no loss of power or rough idle, any insight?

 

I would suspect that in changing the O2 sensor you disturbed something in the air intake system. P0171 and P0174 (I can find no listing for P0170) indicate lean mixture on both banks. A usual cause is a vacuum leak. After clearing the codes the CEL will come back after 2 drive cycles if the problem still exists. A search for those codes will reveal many threads that discuss causes and fixes, but I would check anything that was removed to access the O2 sensor.

 

Thanks I know from being around the p0170's usually indicate a vacuum leak, I just don't understand how removing the air box could create all the mess. I'll check the usual suspects and check for any lose connections. Thx clyons

 

Found vac leak in the check valve coming from the brake booster. I mixed some 2 part epoxy and put it on the holes on the check valve and let it cure. Problem is fixed for now, I'll replace that assemble when the parts come in.