When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Hummer H3For the Hummer driver who wants the rugged look and off road capabilities of the Hummer, but in a smaller size and with a more fuel economy friendly engine.
Hoping to get some insight on some emission readings and graphs on my 2008 5 Cyl (111,000 miles). These readings came from a Veepak OBDCheck BLE bluetooth scanner paired with the Car Scanner iPhone app. No codes other than P0300 and no noticeable performance drops. Some background: replaced OEM exhaust manifold/catalytic converter with Walker manifold, replaced upstream and downstream O2 sensors with brand new OEM sensors, and replaced ECT sensor on June 8. Not really related but I've had P0300 code for years now, with a frequent rough start unless I press the gas and hold the RPMs around 2,000-3,000 for a few seconds (
). Can't be positive, but I think I have soft valve seats on one or more cylinders. Also, main catalytic converter has been burned for years and I have not replaced that one yet.
But for the actual emission tests, you can see below that I have "not passed" listed for Evap system, secondary air system and O2 sensor heater. I can't tell through the app what specifically might be the issue. Again, no codes thrown ever for any of these systems before. I've been doing some research to try and learn more about the Evap system and common failures but haven't seen anything definitive.
Emissions Tests
Here are a few other graphs that might help shed some light on anything specific I should look into (images captured at idle after driving in town for 30 minutes:
Evap Pressure/Evap Purge combined
O2S1 volt/trim on left and O2S2 volt/trim on right
As you can see, I'm not getting any readings for the bank 2 trim and I don't know what that means. Any help or direction I should focus would be appreciated.
Always wondered about SeaFoam. Have you run some through on yours @hummerz ? I put two bottles of Techron in not that long ago but didn't really notice any difference. Actually thought my rough startup issues got slightly worse and became more frequent after switching to Top Tier gas (Phillips 66) only and the Techron.
Help with Emissions Readings
