Anyone have any ideas on what would make a 1998 prelude Vtec with a 5 speed manual set codes P0170 & P0172. The car has 66 K on it timing belt was just changed last week. It experiences idle surges and stalls but only intermitantly, sometimes runs great and a few minutes later not so great. It's my neighbors car and he is hesitant to let the same mechanic keep working on it, seems to get worse each time. Ran great till they put a new belt on it, then they somehow broke the belt when he took it back cause it whined like it had a blower on it. They told him the codes were normal and once the computer recognised the new belt they would go away. I do know these are lean fuel trim codes and they are full of it, I just don't know what on a prelude would set these codes. Thank you for your help.

 

i have no idea what those codes are can you get the real check engine light codes instead?

http://www.hondaprelude.to/art....html

 

These codes were pulled using autotap and are generic obd2 codes. P0170 is "fuel trim bank 1". P0172 is "Fuel Trim System Rich Bank 1". I will print off the intructions you posted and let him try that. Thank you for the suggestion

 

uhh....

new timing belt...now running lean and idle is off.

I would put money on it that they did not align the cams properly when they put the belt on..one or both of the cams are either advanced or retarded effing up your fuel and causing the shitty idle cause they are opening too early

 

It ran perfect for a few hours after all the vac. hoses were replaced. Seems like a incorrect cam timing would cause problems all the time but it would be worth looking into. Thanks