theTorinoguy

I took my fiance's VW 1999 Beetle to the auto parts store and they put the machine on it. The code reads P0172 (system too rich bank 1). I had a mechanic replace the back O2 sensor. Could the front O2 sensor need replaced also? Please help thanks!

3drwhore

what makes you think its the O2 in the first place? and if you did check the voltage on the o2 it would be the pre cat not the post.

theTorinoguy

well thw first thing my mechanic thought was the O2 sensor so he replaced the back one (pre cat i guess) then I took it to Autozone today and the first thing that came out of his mouth was that it was the O2 sensor. I told him I already replaced the back one and he said he was thinking it was the front one.

theSLOWone

check your hoses, usually an o2 sensor with set off a cat code. you could have a kink in a hose to where its building too much pressure so in-turn will tell the system to use more gas and there you go, running to rich. that or take it to john the diagnostic guy.

3drwhore

what sort of hoses are you talking about?

theTorinoguy

I don't really know much about VWs, so what hoses and where are they located. because if it is just a kinked hose hopefully i can fix it and the light will turn off...lol thanks

theSLOWone

the hose from the intake mani to the fuel pressure regulator or vacuum hoses in general

hmmracing

i love people from autozone who know nothing about cars

this guy is the closest one, i can bet you, your fpr is bad, pull off the vacuum line and suck on it, if you taste fuel its bad and that is your problem,

if you had a broken vacuum line its would have a bank 1 lean code,
those cars hardly ever throw a rich code unless your vacuum line has been broken for a long ass time,

theSLOWone

yeah my car car was only running 15psi for the longest time and then i finally threw a too lean code and i touch the hose and it broke right off.. so it sounds like something may be clogged or pinched..