Do you guys ever have any problems with emissions? I found a completely stock 997 I was looking at buying with the options I want. Car has 30k miles now but from new until 2010 it only had 6k miles put on it. I was going over the carfax and noticed 5 failed emissions test starting from around 5k miles up until recently? Car was alway retested a couple weeks later and passed? Should I be concerned about this? My modded 996 Turbo has passed emissions with flying colors every time? Not sure what to make of it and it makes me nervous about buying it now!

 

Failed emissions for what reason? Lots of reasons to fail.

1. Was there a CEL?
2. Were there cats on the exhaust?
3. Have the O2's been replaced?

Stock 997, I'd lean toward o2 sensors. However, if it has a history of failing emissions, I'd be a little cautious. If you can get information on the failures, that could probably help you determine what the history is/was.

 

Also, could be something as simple as battery disconnected just prior to emissions test.

 

I agree. If it wasn't driven much maybe the battery went dead a lot so it would fail for not being ready.

 

One possibility I've experienced is if you re-flashed the ECU beforehand you have to drive it enough for all the ready indicators to reset. There's a specific duty cycle called-out which is like 40 miles of driving in different conditions etc. but I didn't do anything special, just drove around normally for a couple days then retested and passed fine.

(Here in California OBD-II cars simply get an ECU code scan now; no more tailpipe sniffer or dyno rollers. And checking the ECU codes yourself before you go is always a good idea.)

 

Completely stock and failing emissions then passing a couple of weeks later reads like the car just wasn't driven enough -- or it was driven improperly -- and the readiness monitors were no set to complete when the car was taken in.

When I take my cars in the tech checks the readiness monitors are all set to complete before he hooks my car up to the computer. If he hooks it up first then finds the readiness monitors are not set that's a "fail" and I have to pay to have it retested.

'course, I check myself before I visit the station to have the cars checked.

Be sure you give the car a thorough road test, drive it long enough and under a variety of conditions -- city stop/go driving, boulevard cruising, highway driving -- that the DME manages to set all the readiness monitors to complete and the CEL remains dark.

You can take an inexpensive OBD2 tool with you that at least lets you check for any active, pending or permanent errors and lets you confirm the readiness monitors are all set.

 

The seller said it failed due to an exhaust system that was on the car! It now has a stock exhaust and I am unable to confirm why it failed! Appears to have not been driven much early in its life. I decided to pass on the car! Decided I want PCCB anyhow! Thanks for trying to help out guys!