Detail: Took Tahoe for a Smog test and test station won't accept car because the computer hasn't reset to 10, only 8 points and was told to drive the car around until it completes the cycle, then bring it back. How do I know how long and how far to drive it? Been driving 50-60 miles for 4-5 times.
Solution: Some monitors in the computer may need 500 miles of different driving styles and speeds before they are happy and many "start from cold" driving cycles. DON'T RESET anything and DO NOT let the battery go dead or you will have to start over. , Hi, a 6ya Mechanic can help you resolve that issue over the phone in a minute or two. Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck! , I would suspect fuel pump before an odd ecm problem. When was you last fuel filter? An extremely dirty filter will wipe out these fuel pumps if left in play too long. , check starter , Change your fuel filter, it may have gone it's life time and is getting to dirty to let fuel flow properly. Your fuel pump to may be getting weak, if the fuel filter is dirty the pump works harder and heats up and could be over heating the fuel pump relay too. The fuel pump relay i believe is in the glove box behind a panel that say relay, there should be (3) in there and the middle one is the fuel pump's. switch then around after you change the fuel filter and if you get a chance, check your fuel pressure at the shredder valve. Good luck and hope this help's if there is a Auto Zone around you, you can ask to use the fuel pressure gauge to see what fuel pressure you have and they'll have the step by step instructions on how to do it and takes about 5 min to do and will have the fuel filter and step by step to replace that too. Keep me posted, be glad to help. , Drive cycle has to do with normal everyday type of driving. So many stops, so many miles, fast driving, slow driving. My car went thru a drive cycle in about 38 miles on my way to work. My daughters took 3 days and about 78 miles. So just drive it like normal. , P0420....Catalyst System Efficiency Below Threshold (Bank 1) i think one of the O2 sensors isnt working ,now they can be tested with a automotive multimeter but you would need basic knowledge to be able to do this so i would advise you ask a local mechanic to test them for you ,you do not need a code reader to diagnose any electrical fault on a motor vehicle only a meter ,its the only way i can diagnose anything on europeon market vehicle especially from 2005 as the software is all encrypted ,in europe they put a probe up the exhaust and run engine at 2500 rpm try plugging the OBDII in and a lot of cars will lock up with the immobilisor .