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Q: check engine light stays on on 2005 Chevrolet Astro

I have a 2005 Chevy Astro Van I use for my job. I went to get it inspected in Feb and now its April and still not inspected. I went to my mechcanic and he put in a new oxygen sensor. drove for a day and it came back on, now I just got a catalic converter put on. I keep getting it reset, then not enough data, light goes back on. Still not inspected and i got 1 ticket already. I am going back on mon for the scan of the car for $80.00 .I put in 600.00 so far and it still isnt fixed Help I am so frustrated. Any Ideas anyone
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you replaced the cat and o2 sensor for 600?? i bet you used an aftermarket cat which will not work. you need a factory cat which costs in excess of 600.

what codes did you have and did you have a full diag??

thanks for using repairpal.

I got the cat today and he charged me 200.00. He gave it to me at cost. I hope I didnt get n aftermarket cat. I will ask him that. I am going tomorrow or monday for the full diag test. First their were 4 sensors. Keep driving and got down to 3 now 2. I get it reset every other day i feel. He told me today to drive 100 mile cycle before the test. Does that mean drive 100 miles and then pull into in shop, or do it in a few days. Thanks for your help
the drive cycle will not work while you still have problems with the light. you could drive 100 miles and never set a monitor.

this is my idea. do not re set the light. there is freeze frame data the tech needs to help diag the truck. from the sounds of it, you need a new shop that can fix this without throwing parts at it hoping it will fix your truck. afterward, let them do the drive cycle as it is a very specific way to drive the truck to make the monitors run. it sounds like you have been jerked around. i am sure you are frustrated and now it is time to find someone who can actually help you.

try our directory tab at the top of the page for a list of shops in your area.

good luck

Autotap® OBDII Diagnostic Scanner
General Motors Driving Cycle

A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

Reprinted on OBDII web site courtesy of General Motors Corporation
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