Reuben

Just failed annual DMV inspection for the first time.

In idle mode the hydrocarbon (HC) ppm read 467 (standard: 220) but CO%, CO2% and 02% were absolutely fine, and in High Idle the HC reading was 29 ppm.

Any ideas before I head off to see my mechanic about this?

Thanks

vincer77

Sounds like maybe cats.

tbil

Mine failed in CA this year for the same reason, posted a thread with the details a few months back. Local shop replaced the plugs and it passed. They had about 15k miles on them, made a big difference....

Steve Weiner-Rennsport Systems

Reuben,

There are several causes for high HC's that include:

1) Old oxysensors
2) Old spark plugs
3) Leaking valves

Make sure your shop replaces the oxysensor if it has more than 40K on it as they can oftentimes function (slowly) but cause a problem like this.

Plugs with more than 10K on them should be replaced before smog testing for best results.

Do a leakdown test to see if any of the valves are leaking; it may be simply carbon buildups and staking the valves can help. That's a procedure for an experienced engine guy. The other thing that can really help is a large bottle of Techron followed by a good "Italian tuneup".

Hope this helps,

Reuben

Thank you for the advice, all.

Steve - mazal tov on your new website, too. I will send you some feedback when I get a chance.

Steve Weiner-Rennsport Systems

Thank you, Reuben,.........

Please keep me posted on this.

ble2011

I'm so glad I don't have to have my 993 inspected. Don't know why - maybe too old (no news is good news in this case). My 2 other cars get the annual letter and have to be tested. Great to hear yours finally passed.

AOW162435

So, are you a TROLL?


Andreas