Recently I started getting a 443 and 231 code along with a CEL. After the 443 code I would also no longer get any boost. Once I clear the codes I would have boost for a short period but it would be sporadic and then no boost at all. It happened twice that the 443 and 231 codes would pop up with a CEL. The last time I cleared it which was 2 weeks ago I had boost for a few days and then it went away but no CEL this time. Yesterday I checked and I only have a 443 code. I noticed that after I cleared the code and restarted the car it would idle rough for about 2-3 seconds and then even out.

One thing I'm about to do is change out the thermostat and coolant temp sensor. The reason i'm changing it is because when it's colder than 40 outside the car would never go to full normal temp no matter how long it ran for. Once it got to 45-50 outside it would go to normal. I was wondering if that could be causing the issue's that i've been having? I greatly appreciate any help and advice you may have.

 

How about you tell us what the codes stand for as hopefully you have already looked them up ??

 

231 is fuel trim, and 443 is catalytic efficiency. Neither if those should be causing boost issues, i wouldn't think. Are those the only codes you have?

 

You should check ever vacuum hose to see if you have a leak some place from age might be cracking or split or something rubbed through.

The cat might be getting plugged which would hinder the boost and cause the code ?? Just a guess.

http://www.matthewsvolvosite.com/for...hp?f=1&t=23302