Hello Is there a way to , briefly, lower the Co emissions. This just for the time to be sure 100% to pass regulation. I would think increasing air flow or lowering fuel amount ?? Grts Patrick
Could try raising engine temperature. I’ve done this by temporarily blocking the radiator (s) Or decrease overlap with cam timing, not so easy. Or as Tim said, new cats, factory spec
Try just doing basic maintenance and have everything work properly. There is no magic here...even in the people republic of kalifornia
Are you needs the same as for when the car was new? Or are they expecting your car to "pollute" less?
I'd go with FBB on this one. Make sure your plugs are new, the car is really warmed up beforehand - as in drive the snot out of it for 30 minutes. Depending on year, the bar is pretty low so if things are even barely working, you should pass. New cats or borrow a set if you have to. Run a full gas tank treated with Chevron Techroline or other injector cleaner. You might need to have your injectors cleaned or replaced. If replaced, check OSide Tiger for replacements with 4-hole atomizers. Good luck, but you probably will not need it.
1) Make sure that the coolant temperature is consistently above 176ºF / 80ºC. The Motronic ECUs do not go into final fuel mapping until they are reading coolant temps 176ºF+. If they are under the temperature the ECUs will run in secondary fuel enrichment mapping and the engine will not run as efficiently, because it is adding extra fuel in an attempt to keep the cats lit and hot. If the temp does not get over 176ºF / 80ºC then you will want to put in a new thermostat. 1a) make sure that your coolant temp sensors are in good condition. If not replace as needed. 2) Make sure that the resistance on your MAFs is at least 383Ω ohms. If not adjust them accordingly. 3) Make sure your catalytic converters are in good condition. 4) Make sure all spark plugs are in good condition and properly gapped. It would even help to disconnect the battery, reconnect the battery, then let the Motronic ECUs relearn the initial warm up parameters. After the reset and relearn take the car to get tested. And MAKE SURE the engine it at the proper operating temperature before and during the test! Some have run the fuel tank until the fuel gage shows "empty" and then added 3 gallons / 11 liters of pure alcohol, ran the emissions test, then topped up with normal gasoline/petrol after the testing has completed. But that is a last ditch effort
The fairly easy way to try would be connecting two 1 Kohm resistors in parallel to the coolant temp sensors (CTS). As this would cause difficult cold start, the resistors would have to be "switched on" once the engine has warmed-up. For example, at 80C, the CTS resistance is 322 Ohms. Adding a 1 Kohm resistor in parallel would bring the total resistance down to 243 Ohms which represents 90C coolant temperature and this would full the ECUs to make the mixture a bit leaner. PS: I have no associations with VW CTS Chart: Image Unavailable, Please Login