2003 Yukon SLT 5.3L Engine not Ready for emission test help

[zmann96]

I finally got the codes gone. I drove it 200 miles after the last time I cleared codes. I went for the inspection and the State computer said the system was not ready for emission test. I drove it again this morning and now have 315 miles. I found out my OBDWIZ computer software did this check. So it still isn't ready. I found a driving sequence that will clear it for the emission test. I just don't know where to do this, I can't drive 55mph on city streets, I can't or shouldn't slow down without braking from 55mph to 20mph on my highway that the people are doing 70 - 80 mph. Is there another way to make it ready for the test? It also said cold start engine turn on AC and rear defroster for 2.5 minutes then as soon as possible do the 5 minutes of 55 mph then down to 20mph and do that twice.

I really thought I could just put miles on the engine???

BTW there are no codes

 

[OR VietVet]

Looks like you need to have a qualified tech monitor oxygen sensor operation and fix as needed. Plus look at the evap system for leaks and operation.

 

[zmann96]

Looks like you need to have a qualified tech monitor oxygen sensor operation and fix as needed. Plus look at the evap system for leaks and operation.

I did put in a new vapor charcoal canister and checked all that when i did it. I've done the evap leak check a bunch of times.

 

[zmann96]

My question is, it's not coding after 314 miles so far and my Fuel trims came down form being pegged at 25% to almost normal. Will it eventually be ready for the emission test or does it have to go thru that crazy sequence?

 

[PG01]

My question is, it's not coding after 314 miles so far and my Fuel trims came down form being pegged at 25% to almost normal. Will it eventually be ready for the emission test or does it have to go thru that crazy sequence?

Keep driving, seriously... trying to meet all the ‘conditions’ isn’t going to happen on a few drive cycles. As long as no check engine light pops it will eventually pass those self tests. In NY you can have 1 (or 2, I forget now) monitors not ready and as long as no cel you are going to pass. Evap, iirc, takes the longest. I just did this with my fil 03 suzuki at the beginning of the summer. I drove that car a few miles every morning before work for 5-10 miles because I let the battery die and I had to go through all the monitors... pia

 

[zmann96]

Keep driving, seriously... trying to meet all the ‘conditions’ isn’t going to happen on a few drive cycles. As long as no check engine light pops it will eventually pass those self tests. In NY you can have 1 (or 2, I forget now) monitors not ready and as long as no cel you are going to pass. Evap, iirc, takes the longest. I just did this with my fil 03 suzuki at the beginning of the summer. I drove that car a few miles every morning before work for 5-10 miles because I let the battery die and I had to go through all the monitors... pia

Thank you, I'll keep driving it.

 

[Rocket Man]

The EVAP takes forever and no there’s no way that I know of to do that stupid drive cycle safely unless you live way out in the country. Just keep driving and checking. Luckily due to COVID most states aren’t worrying about expired tags, at least they aren’t here.

 

[zmann96]

The EVAP takes forever and no there’s no way that I know of to do that stupid drive cycle safely unless you live way out in the country. Just keep driving and checking. Luckily due to COVID most states aren’t worrying about expired tags, at least they aren’t here.

UGH! yeah when I read that crazy sequence I thought who can do that safely? OK, I'll keep driving and checking. Thanks

 

[George B]

I just did this too. I can have one monitor not set. A couple good 10 minute highway runs will do all but the Evap.

 

[zmann96]

I just did this too. I can have one monitor not set. A couple good 10 minute highway runs will do all but the Evap.

This is such a pain. I've done 2 150 mile runs, mixed with highway and city streets.