96 Volvo 850 GLT with EFI-443 Check Engine Code

bluezero000 · Post by **bluezero000** » 31 Dec 2004, 10:26

My CEL is back on again, 1000 miles after rear O2 sensor replacement and 700 miles after starter/timing belt replacement. The code is EFI-443, which is efficiency. As I inspected the hoses/ducts around the air cleaner, I found that the aluminum pipe (which goes from the air cleaner to the back of the engine) is not tightly sealed on the engine end. The blue circle in the picture below shows where the pipe connects to the engine:
http://pg.photos.yahoo.com/ph/wang_wanj ... CBn84lqfUQ

Could this be the cause of CEL? Will air filter replacement help? Anything else I can check before taking it to a mechanic?

Tons of thanks.

Post by **matthew1** » 31 Dec 2004, 11:50

That surely could be a cause of that code. Any introduction of air (or fuel) once past the initial measurement points (in this case, the MAF) will cause unbalanced fuel/air mixtures and trigger codes.

bluezero000 · Post by **bluezero000** » 31 Dec 2004, 15:06

The pipe is intact elsewhere, so can I just seal the pipe end with some kind of tape? Or do I need to replace the pipe? Is it called mass air flow pipe? Thanks again.

bluezero000 · Post by **bluezero000** » 07 Jan 2005, 22:02

Unfortunately, sealing MAF pipe end doesn't prevent CEL from coming back.

AB · Post by AB » 22 Jan 2005, 19:43

I just saw your posting and I just got a "check engine code too... A week ago when I changed the RPM sensor on the engine, I accidentally broke off a piece of the tube you are talking of, but I "Repaired it". I just ran out and checked it and my repair didn't hold, so noe I am wondering if that may be the same problem, unfortunately I do not have access to an OBDII reader so I am a little in the dark... I will try to re-seal it and see what happens.