01 Chevy 2.2L Tip for running EVAP monitor test

[ephratah service center]

This is the second 2001 chevy with a 2.2L that I have had to do this on in order to get monitors to run for NYS inspection.
There is no EVAP bay test available only a purge and seal test.
The last car was a 01 Caviler I had driven over 100 miles to try to get EVAP monitor test to run with no luck.
The current vehicle that is in the shop I have driven over 50 miles in attempt to get monitors to run is a 01 s-10 pick up with a 2.2L.
I have had to let both vehicles set over night and in the morning hook up the solus and get into the EVAP data screen. I start up cold and let idle with headlights and A/C on max. Let idle for 2-3minutes until I see the purge valve activate and then raise idle up to around 1300 RPMs (2 or 3% on IAC) while watching vent valve when vent valve closes I do a drive cycle. Both vehicles have completed EVAP monitor test with in 3-4 miles.
Hope this may help some one out that has had this problem.

[greasybob]

My concern with doing service bay evap tests is that it only looks for large leaks. What good does this really do if a small leak will turn check engine light back on, a purge and seal test will only tell you if purge valve and vent valve are working. Testing with a smoke machine with a leak down gage or leak detection capabilities is still the best method and probaly the quickest. Just a thought.

[Crusty]

My concern with doing service bay evap tests is that it only looks for large leaks. What good does this really do if a small leak will turn check engine light back on, a purge and seal test will only tell you if purge valve and vent valve are working. Testing with a smoke machine with a leak down gage or leak detection capabilities is still the best method and probaly the quickest. Just a thought.

The diagnostics capability of most of today's vehicles is VERY accurate. How long does it take to go over EVERY INCH of a complete fuel system? Tank, filler & vent, cannister, lines, vent valve, purge valve, some have isolation valves too. An example is a 2002 Nissan Pathfinder... you can hardly even SEE one of the valves at the rear of the tank above the axle, let alone shine your UV light from every angle that is possible for a small leaak to escape from.
On a 2009 GM uplander with EONV, the evap monitor didn't complete until I ran the GM Service Bay test which then completed the testing for P0442. And I think a large leak is under another P04xx number (that vehicle uses about 6 P04xx self tests).
What Jim is talking about is raising the rpm so the system completes it's own self test, completes the EVAp monitor, and then if it didn't set a code then,... then you're good to go.

[greasybob]

Thankyou Crusty for your reply and your insight and thankyou to Ephratah for your tips on running the evap monitors. I understand the importance of running the monitors especially if your testing for state certification. As far as I know I've never seen a data pid for desired fuel tank pressure so a monitor test is the only way to verify a repair was successful from the vehicles point of veiw. I was just wondering about the logic of a service bay test that only check for large leaks if your repairing a known leak for the sake of keeping the check engine light off and if you can program an ecm to do a self test on command for a large leak why could you not program it to check for small leaks as well. A problem we have here in wisconsin is you get a warm spell in december or januaury and cars will start running the self tests and fail and you might not be able to get it to run a monitor test again till april. Thats why I've gotten into the habit of verifying my repairs with the tests on my smoke machine.Again thank you for your reply and your insight.

[Crusty]

Thankyou Crusty for your reply and your insight and thankyou to Ephratah for your tips on running the evap monitors. I understand the importance of running the monitors especially if your testing for state certification. As far as I know I've never seen a data pid for desired fuel tank pressure so a monitor test is the only way to verify a repair was successful from the vehicles point of veiw. I was just wondering about the logic of a service bay test that only check for large leaks if your repairing a known leak for the sake of keeping the check engine light off and if you can program an ecm to do a self test on command for a large leak why could you not program it to check for small leaks as well. A problem we have here in wisconsin is you get a warm spell in december or januaury and cars will start running the self tests and fail and you might not be able to get it to run a monitor test again till april. Thats why I've gotten into the habit of verifying my repairs with the tests on my smoke machine.Again thank you for your reply and your insight.

Thats a good habit to have. Personally I double, triple & quadrouprle check my work regularly. It might not initially seem productive but when other things happen later, I can be assured it WASN'T what I did last time (unless a part or component has failed since the vehicle left) Mr Everett Sinchu gets a lesson on quality or gets sent packing. Sometimes a second or third code appears because the first code was inhibiting the self test to check for the second or third. It depends on the manufacturer & their code set criteria.
If you found a leak with the smoke, verifying the repair with smoke is good.
You can also run all the monitors and let the vehicle decide the completeness of the repair.
The P0442 won't even try to run until some of the other P04xx self tests have run & completed without seeing a failure, so I'm not sure it's only looking for a large leak. It could be that the newer EONV (that started being used on some models in 2003??) is also looking for the 0.020" leak, not just the 0.040" leaks of yesteryear.
The systems are constently changing, adapting & evolving so constant reading is imperative.
The GM manuals have a good description of the "service bay test" which expands the temperatures the self tests would normally need to complete the monitors and allows self testing to occur in a "real world" service envirionment, so it's worth reading.
EVERY training course I ever went to forced us to RTFM. That's it, that's all. RTFM. RTFM. RTFM. (LMAO)
Doctors have it EASY.... they bury their mistakes, they only have 2 models to work on, and they havn't changed in 10,000 years-(LMAO)