This is something you might try. And it wont cost much.
Get a bottle of Sea Foam [Most auto parts stores have it] siphon out the old gas put in the best high grade you have in your area. I would put in about 3/4 of a tank and add the can of Sea Foam. Put the Sea Foam in first so it will mix better. Go for a drive. Use your power key and open it up. Or if you want to see what has build up in your motor. Put some catch pans under both muffler weep holes.[weep hole will be at the lowest end of the muffler] With the power key on' run the RPM up a few times then let it idle for a while. [You might repeat the raising of the RPM a few times then idle it again.
A mechanic told me about Sea Foam. I have never cared much of engine additives but this one seem to work. The first time I used it was just after putting in new injectors. I let mine set in my shop and run for a while It left two black 6 inch carbon stains on my shop floor. I used it again a few days ago after getting my 405 HP working again. I now have a new set of stains.
California is a beautiful place to live I like it there but too dam many rules. It's not as pretty in the armpit of America but we have more freedom. Fast car's being one of them.
There are some good people on here that might have a better solution to your problem. This one worked for me.
Good luck with the inspection.
