Howdy,
I have no questions, but wanted to toss this info out into the ether as googlefood in hopes that it helps someone.
The wife's lately-seldom-driven '98 New Beetle was throwing these check engine codes:
p1582 idle adaption at limit p1128 long term fuel trim sys too lean.
The 2 codes my independent tech first tried to address by cleaning up the throttle body with carb cleaner and degunking it. That made us feel better but didnt' fix the problem. :-)
Next step was a similar cleanup done to the mass airflow sensor (MAF). Once that was done, voila, codes gone and never came back.
I was also hearing a sucking noise near the firewall.
The sucking noise turned out to be a cracked very poorly engineered vacuum hose coming off the brake booster. One shop said I had to go to VW for the part. Another independent said that was ill advised as the hard plastic teh oem part uses will just crack again sooner than it should. He used some hose he had laying around to repalce it and it's been working fine.
Third, the original Michelins on this car went for 75000. They were quite bald, and the tires were cracking --almost to the point where you saw the belt separating from the tire. But here's the amazing thing: they were still some of the roundest, smoothest at speed on teh highway tires I've ever had. And here I always have been told Michelins are overpriced. I haven't had a Dunlop, Kumho, or Firestone stay round for more than 35k much less 75k and nearly falling apart. Kudos to Michelin.
Fourth, the driver's door key lock became so hard to operate that I thought the key would break. Tech ordered a new door cylinder from VW matching the existing key code. Took a couple weeks to come in, but the replacement was dead easy once it did. And it didn't cost that much either.
Finally, on a more obvious note the following codes I saw once: p04422 Evap small leak p0455 evap gross leak
were corrected by tightening the gas cap.
Happy driving.
Cheers, Todd