rickybiggs99 0 Posted June 29, 2006 I bought an exhaust gas analyser at the weekend 'cause I thought the car was running a bit rich.I hooked it up and it was showing 1.65%.The haynes manual says it's supposed to be 1% for a phase 2 but I could only get it down to 1.35% with the mixture screw fully out.Is this figure ok or do I have a problem? Share this post Link to post Share on other sites
jim21070 2 Posted June 29, 2006 That is fine, it's an MOT pass (limit 3.5%) so if the car is running OK in all respects, no worries. The mixture screw is very insensitive. Before testing however: Check that your butterfly is returning to its stop and the TPS is operating normally. Check the Throttle Body, AFM, breathers and all pipework is clean. Ditto air filter. Clean as necessary. I guess you have a Gunson CO meter. If so they are hard to use. Let it stabilise for at least 30 mins in free air before calibrating it and then watch that the calibration point (2%) remains stable for a further few minutes and make sure the sniff pipe is well up in the exhaust, ensuring you can hear the pulse pump "huffing". Then let the reading stabilise for a good 2 mins. Check that not too much water is in the sniff pipe. Make sure the engine is good and hot during the test. Check that after your test thst the meter returns to calibration back in free air. This may take 5 minutes or more in still air. Failure to observe all of the above can lead to very misleading readings on a Gunson. Share this post Link to post Share on other sites
