Vauxhall Vectra 1997 1.8 x18 - High CO and HC on fast idleArchived Message
Posted by Dave Mittell on July 21, 2005, 1:20 am
high co on fast idle and high hc on fast idle and idle. Exhaust manifold was cracked so replaced this made a small improvement so changed oxygen sensor and made a small difference. No fault codes showing fitted new air filter, checked breather system, tested all relevant sensors only one that was slightly out was cam sensor. Also Egr valve is reading as being 17% open after revving engine to fast idle for 1 minute. Should this be the case? Tested vehicle and warmed up on machine from cold emmissions were fine. Took vehicle for drive by time i reached test centre it failed. Co 0.65% hc267 at 2500 rpm and co0.47 hc 226 at 850rpm. Does anyone know of any common faults on these as i am now beginning to struggle as to where to look next. And will the cam sensor fault cause excessive emmisions? o2 sensor switching fine. lambda reading is 1.03 at 3109 rpm if thats any help gonna get it on the emmissions reader again this afternoon so will get o2 readings etc. Whilst testing it this morning the emmisions dropped to what they should be for about 3 minutes and then jumped back up again. So its totally baffled me now!!