Can anyone tell me more in depth what this code means, and more importantly, how to fix it? The guy at AutoZone only told me the O2 sensor, but wouldn't really give me any more information than that. They also wanted like $350 for it!! Is this normal? I need suggestions, please!

 

Start by checking for vaccum leaks.

 

How would I do that? I also heard that if there is a vacuum leak you would know, because the car would idle rough or run really bad? My engine runs really great, just like it did 10 years ago. Just wondering. Thanks!

 

What model and year is it?

 

Sorry, its a 1996 960

 

Sometimes spraying Carb cleaner around the hoses and connections will find it. Others you have to add pressure from the air induction hose to find them.

 

1997 Volvo 960 po172 code. I have replaced the o2 cancers both of them. replaced the pcv valve,the black box below the intake manifold. vacuum hoses the power assist for the the brakes (it had a vacuum leak) replaced the intake manifold gasket. replaced the mas air flow censer. cleaned the fuel injectors or replaced all of them. installed all new spark coils. stil have po172 code. HELP MY NAME IS JIM