You are right about that.  My '97 EVC had that problem before I bought it. A misfire (bad wire) resulted in the cylinder washing down and losing compression, and then the unburned fuel took out the CAT and nearly set the van on fire. The PO drove way too long with the check engine light on, and ended up putting in a new engine and complete exhaust for about $8k (dealer). If the idiot doesn’t pay attention to the idiot light . . .

Now I've noticed that the idle on the '87 is still surging a bit, like up and down 500 rpm a couple of times every once in a while.  AAARRRGGHH!  Only thing left is the idle control valve itself, or maybe I should just throw in a temp 2 sensor and new O2 sensor, even if they measure to spec per Bentley.

Stuart

-----Original Message-----
From: Dennis Haynes [mailto:d23haynes57@hotmail.com] 
Sent: Tuesday, November 25, 2014 2:53 PM
To: 'Stuart MacMillan'; vanagon@GERRY.VANAGON.COM
Subject: RE: '87 Westy running problems solved-OBD comments

Don't believe it. It still comes down to bad information, bad processing, or a physical problem. Troubleshooting injector and cylinder balance are basic skills and good routine maintenance includes cylinder balance testing to make sure you don’t have lean misfires or other fuel delivery problems. More than one engine has been destroyed from a lean cylinder melting a piston and burning a valve and that lean miss means unburned fuel (excess HC) to destroy the catalytic converter. 

Dennis