In this video I'll show you how to complete a drive cycle and pass inspection after turing off your check engine light.  It is true that your car will not pass inspection if the check engine light is on.  However there is more to it than simply turning it off.  By the way the easiest way to turn off the check engine light would be to disconnect the battery for 30 seconds.  Inorder to pass inspection your car needs to complete a full drive cycle so that all (8) internal monitors have a status of "Ready".  If any of the (8) monitors have a status of "Incomplete" that means you have not yet completed a full drive cycle and you need to drive your car around more.  Your car will need to experience city driving situations and highway driving situations inorder to complete a full drive cycle.  

Usually if your check engine light is on that means you need some repair work done on your car but that is not always the case.  I drive a 2002 Chevy Impala and the check engine light has been coming on for about 4 years.  The trouble code is "P0420".  That means the catalytic converter is functioning below the normal efficiency levels.  Back in 2007 when I first noticed the problem I had the catalytic converter replaced.  At that time the performance of the Impala was greatly reduced.  Specifically when ever the accelerator was pressed there was a significant time delay before the car would accelerate.  It almost seemed as if the transmission was slipping and then suddenly it would catch and the car would accelerate.  The problem however was not the automatic transmission.  The problem was the catalytic converter.  There was a carbon blockage that clogged the air flowing through the power train.  Exhaust was escaping through the EGR valve because the catalytic convert was blocked up so much.  So I bought the new catalytic converter.  The cost was roughly $800 as I learned that my vehicle was manufactured to the California emissions standards and not the federal emissions standars.  That was news to me.

About two or three months after the catalytic convert was replaced the check engine light came on again.  This is around the time I asked for an OBD-II code scanner for Christmas.  The same "P0240" trouble code was being stored in the engine control module.  The catalytic converter was under warranty so I had it replaced thinking it may have been defective.  Again the "P0420" trouble code came back.  At this point I started to see a pattern.

There was no performance problem with my car anymore.  That had been resolved after the first catalytic converter was installed.  The only issue was that the check engine light kept coming on.  The Oxygen Sensors before and after the catalytic convert have been tested and I was assured they were functioning properly.  If the Oxygen Sensors are out of whack that could possibly trick the engine control module into thinking that there is a problem with the catalytic converter.  So that was ruled out.  

To this day in order to pass inspection I have to erase the check engine light and complete a drive cycle.  Only then will my car pass inspection.  Of course two weeks after the inspection the check engine light will come back on.  Hope this informations helps someone out, or maybe you have your own theory about whats really wrong.  I would love to hear your thoughts.

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Thank you very much for posting this very helpful information. I also checked out the video and it was extremely helpful. I own a 2010 Chevy Impala and I've had a check engine light for about a year now. The car drives with no problem but when I went to go do an inspection in the state of Delaware I failed. I try to do the right thing and take it to a mechanic he charge me $100 for the diagnostic and then informed me that all together it would cost about $724 to fix all the problems and get that check engine light off. This was very distressing as I am on a tight budget and didn't have that kind of money at this time. Also I don't really trust the mechanic being that I'm very new to this area and feel that it could be something as simple as a gas cap and he's just taking me for a ride. I'm going to get a new gas cap cuz I do need one and buy the cheapest scanner. I'll post the results. Wish me luck!
<p> Was the place you took it for inspection like a inspection only shop? Seems like any one worth a crap would of gave you a little more detail then just &quot;pass&quot; or &quot;fail&quot;. In texas no pass no pay inspections are not legal so you got to go to the the mom and pop shops. You might have to try multiple places and it helps if they have a lot of competition close by. If its a shop that I don't feel comfortable pulling up and getting out with beer and hand it's not the right shop. If you want to try to get it inspected with the check eng. light on then you pull up, and tell them the light is on and most of the time they will say sorry they cant do it or will hook scanner up to see what the issue is no charge, that's you tell them something like &quot;Ain't there special sticker for cars like this?&quot; and before the can answer you say &quot;I know there probably expensive, probably around....&quot; and you add the price of inspection plus whatever your willing to give for it, I usually add 40 to 80 bucks. if no and look pissed move on, if they say no and seem like they feel bad about it that's when you got to put the show on, beg them, act like your gonna cry, tell them about your family, tell them your barely making it or offer them more money, ask if they know someone that can do it, get as creative as you can, and dont give up until they walk off then you put ur head dont on the car roof on your arms and kinda shake like your crying and if they dont work move on before they call police and move to next shop and try again. Option two is to go to any big name auto parts store and most of them will hook a scanner up for free and tell you what the issues are according to the PCM, The problem with the cheapest scanner is it will tell you the code and reset it but it wont tell you when all systems are ready. but do your research becaue it wont always be the part that has a error so just get online or whatever and research. If you are good with electronics you can buy cheap bluetooth scanners on amazon. I love them but they are kinda a hit and miss thing. For $100 they should of of gave you a detailed list, try to get repairs at a place the inspects too. On simpler car issues you can sign up on autozones website and they have free repair manuals If you are any good at turning a wrench. Youtube can be helpful at times but there are also a lot blind leading the blind videos. If you got the repair route, remember research can go long way, my friend was about to pay $600 for a repair at the dealership, I told him to see how much the part itself was online and it was $100, I put it in for him (days to get the part, 15 minutes to install and only needed like 3 tools but he could of done it himself if he had to but gave me a 100 for helping him, good luck</p>
Hello this is strock can you tell how to do drive cycle for chrysler 300m 2000 year
Basically what u are saying complete a full drive cycle turn off check engine light you should be able to pass the inspection
<p>sometimes it takes 300 miles to pass a drive cycle </p>
This helped alot! I'll try and use this information to fixing my car..I have a 2001 chevy impala that won't pass smog, when I took it in the smog technician said that it's not reading on the computer..do you know what can cause this?
<p>Extremely helpful. I have a Honda Accord 2001. Its original Cat was broken last year. I replaced it with a new after-market one from Midas. But after a while the check-engine light came back due to that P0420 code. Midas then changed the Oxygen sensor, but that did not help. They then replaced the Cat with another one of better quality (and I had to pay more), but it did not solve the problem either. I brought the car back to them a few times more, and they could not get rid of the code permanently. I got tired and did not bring the car back to Midas for warrantee any more. But the deadline come for me to have the emission test done. So I disconnected the battery to get rid of the check-engine light just before brought the care in for an emission test. It failed because the car was not ready as you explained. So I disconnected the battery again and followed suggested procedures to get the car ready for a test (while making sure I brought it in for a test before driving it too long and causing the check-egine light to come back). If passed! If I had learned about your experience, I would not have lost so much time and money (bringing the car back to Midas many times and paid extra money). But thank you so much for sharing this very helpful information.</p>
<p>Wow... just wow... My car is a 2003 Toyota Corolla, but reading your story really made me think you were driving the same car I was/am. I've been having problems with the Cat for years, and have had quite a bit of work done in order to pass inspection. Still though, that blasted light refuses to stay dead for long, and it's always the same, lousy &quot;P0240&quot; trouble code. Mine was also apparently manufactured to the California emissions standards, and so on and so forth.</p><p>Thank you so much for sharing your experiences and knowledge here.</p>
What is the drive cycle for a 2003 Pontiac Bonneville?? I can't find it and I don't have one of the gadgets to check
Great advice! I was a little worried that we weren't going to pass our <a href="http://www.abovethefootings.com/index.php?mode=webpage&id=537" rel="nofollow">home inspections in Calgary</a> last week, but everything went smoothly thanks to this post.
I have the same exact problem too. I heard from my mechanic that unless we use a OEM Cat from the Dealer, the dreaded P0420 keeps coming back. No matter how many after market Cats tried upon. <br> <br>These O2 Sensors are so tricky that they are almost fool proof. <br> <br>However, I have also seen people trying the O2 Spacers (Like a 1-2 inch steel tube for the O2 sensor, that spaces out the sensor from the Cat's air flow). This tricks the vehicle's ECM to think that the CAT is still working under normal effeciency. <br> <br>I have also read people using the &quot;DIODE TRICK&quot; where a diode is connected in series to O2 sensors signal cable to drop the signal voltage., again making the ECU think that the CAT is normal. <br> <br>Personally for me the Diode trick did not work. As the ECU throws a new Error code (and CEL) for Resistance Too High on the sensor.
Hey Nate I have the same car. The problem is in fact your Catalytic converter. I have been going through the same process Hear in Texas for the last four years. Five cats later. I finally bought one from Eastern converters online. It was made especially for the impala. So far it works, but the tranny blew so I have not driven the care in a while.
Thanks for the feedback David. Its good to know I'm not the only one! My dad is convinced its a manufacturing problem with the catalytic converters. He was so curious he actually sawed the thing in half and inspected the honey comb filter inside the cat. It was pretty obvious that some of the material inside the cat wasn't in the correct place, and hence impeding the air flow. Let me know know if the Eastern converts cat works out after you put some miles on it. Maybe I'll pick one up. Thanks again.

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