failed smog due to FPR and damper?
 

My S2 failed its smog test for the first time last year. I finally saved up some money to bring it to a mechanic I was referred to. Long story short, he suggested replacing the fuel pressure regulator and damper as they were 'leaking' into the intake. Admittedly, I have a lot to learn. However, I am not following how they will leak into the intake. Isn't it a closed system with the injectors being the part that would leak? I am writing to get some feedback and confirm that I am not getting BSd. I will post more details for posterity after I go pick it up.

By the way, his suggestion didn't help it pass so we had to eventually replace the cat. Although I like the approach to find what is actually wrong I am also leery of the fact that he stretched his original $300 estimate to over $1100 and two weeks :eek:

Thanks for any feedback!

If the diaphragm starts leaking on either the FPR or Damper then gas starts getting sucked into the vacuum system. You can usually tell by smelling the vacuum nipples on each and check for gas fumes, and also checking if they hold vacuum.

So not out of reason as a cause, although they usually lead to difficult starts more than anything.

a bad fpr can cause too much or too little fuel to be going to the injectors, which can make it run rich or lean, and can screw with the emissions. since the injectors are mounted in the intake, he is technically correct. it should be easy to check with a pressure gauge though.

also, if it was running rich and/or leaking into the intake, it could just be the injectors. those should be serviced every few years.

++2&3 ^

9XAuto had a technical info page on ebay a few years ago and offered 944 owners a list of regular maintenace items that should be changed.

Top of the list was the FPR & FPD. So the mechanic began with the basics.

In most posts (Pelican & RL) on CA emissions failures, the cat is at the top of replacement parts.

J_AZ

You guys are seriously unbelievable. That was RIDICULOUSLY fast. Thank you very much for putting my mind at ease. I will post the specifics later as I read lots of threads leading up to this and it was always helpful to see more info. Thank you all again for the fast and thorough responses!