emissions failure

[popone913]

93 Infiniti G20... All the mechanics are telling me it's running rich on fuel... The readings were high on Carbon Monoxide. Is there any adjustment or are there any other people having this problem... There's no check engine light or anything. It runs a little rough at an idol so i'm guessing that if it's rich on fuel that would be the cause. Please reply soon as possible... Thanks!!!

[RED_DET]

Check the maf voltages to make sure they are in spec. Cleaning the EGR might help matters as well and changing the o2 sensor.

[wheelsspin]

CO is a good indicator of a rich condition, but in addition to what else has already been said, faulty injectors or a problem with high fuel pressure( fuel pressure regulator) can cause high CO. A cheap test of the regulator is to disconnect the vaccum line. If it runs good after, it was the problem. Of course, unless you have a fuel pressure gauge!

[Big-Lettuce]

Having a '92 DUB and several other Datsun-like automobiles I can say this. . . If you have concluded that is it running rich then you have a smorgasboard or areas to check, the ECU is set to auto-rich when there is a problem. A dealer or Auto Zone can tell you your ECU fault code in about an hour. However it will take me an entire post to tell you what actually to check and replace. A dirty MAF can be a contributor, however is not the actualy source of your BEEF! A MAF like other sensors is a SENSOR too, however you have a bad sensor on your engine more than likely, and I am not saying MAF either. The most imporatant thing here is the MILEAGE??????????????????????????? How many miles are on the DUB, clean your EGR, yes, clean your MAF, yes, replace your O2, yes, replace your cat, yes, replace your knock sensor!!!!!!! Ever heard of knock sensor? This is the likely cause of your problem. OEM says cat should be replaced every 50k if you replace a O2 and clean an EGR and still use the same old failed cat you'll be back where you started in 6mos or less. Hit the KNOCK hoss!!!!!!