p0172& p0175 trouble

[redmark8]

Hi Everyone! I just registered today, but have been reading this site for a couple of years, couldn't get registered with AOL before but it worked today and got my third gen2 two days ago, a beautiful toreador 98 lsc with 47,000 on the clock. Geno, you will see it soon, that's the good news, now the bad. I have a 97 base model with 103,000 on it, I had one of geno's chip, air filter, and mass air flow on it from my black on black 98 lsc that my son wrecked and it ran great until I took that stuff back out and returned it to stock. Now I have a cel with codes p0172 and p0175. I've spent hours reading about this and cleaned the MAF sensor,sprayed ether around to check for leaks, none found, erased the codes twice and they still come back. I"ve read that O2 sensors are not usually the cause, what's next the fuel pressure regulator and what are the correct readings? Any help would be appreciated. Thanks

 

[GMAN]

You have a vacuum leak. That is first and foremost that you must check first. Check your air tube for cracks, make sure there's no leak there, Check your PCV valve, go ahead and replace it, they are too cheap. The PCV runs to a rubber T then Y's off to the intake manifold. Check that T and make sure it dont like mine.

 

[redmark8]

Thanks, I'll try to check it today and report back

 

[redmark8]

Checked my fuel pressure regulator today, it read 65 psi, went and got the other one off my wreck, it read 60. Went to the store bought a new one , put it in, cleared the code and will read it tomorrow on my friend's guage. The vacuum lines looked okay.

 

[redmark8]

The Y from the pcv looked good, I don't think there's a vacuum leak, it runs very smooth with no stumbling. The new fuel pressure regulator reads 35 with key on engine not running and 60 with engine running. My 98 factory service manual says max should be 45 both ways. Could I have a clogged return line, they are not pinched and look like new from the outside? What else am I missing or just drive it to see if the code comes back. I'd rather be driving my 98 lsc. Thanks again in advance for any advice you guys could shed