Toyota Camry passed HC on smog check but failed CO.

the CO at 25 MPH was .02 over MAX(.45) I've been having trouble with the main electric radiator fan during the 1st test, it was ON all the time, from the

time I turn the key on with a cold engine. I thought that might have affected the high HC numbers. So, for test #2, I put the fan on a switch- when I'm in stop and go traffic I turn on the fan. It's Off when

I'm on the freeway or above 40 mph. When I did the retest, I had the fan OFF. The technician commented afterwards that it looked like it was overheating (I can't get the needle above half way- that's normal) he turned on the heater during the test- I didn't mention the fan switch to him. Other bits of info- I got a K & N air filter in there for the last 15 yrs, I did take it out, wash it and reoil it prior to the first test-should I use a paper filter if I re-test again? This car also has two 02 sensors-I think I changed the lower on yrs ago (the top one prior to the 1st test) & it has 2 cats- both original.

Here's my options the way I see them:

1) go to a 'pass-or-don't-pay station and see if it passes with no further repairs or action on my part

2) take it to some place and have them try to repair it and also see if they do test only afterwards and hope it passes

3) sign up for the CAP program

A couple more questions if I may. Someone told me if I use the CAP program, I may have to leave my car with them for 2 to 3 days while they repair it and

do the testing. This means a 2 to 3 day car rental costing about $100 which I can't really afford- do they actually make you leave your car with them?

And since I already paid the $8.25 for the certificate on the 1st test- will I be charged for it again if I take it to another shop? Any thing cheap and fast to bring down the CO level?

Answer:		Last question first... A CAP station will require you to leave your Toyota Camry with them for a few days. There is no going around this. I don't know of a CAP station or any smog station for that matter that will do an on spot diagnosis and repair. With a CAP station you may even have to make an appointment to drop off your Toyota.   As far as having wired your Toyota's fan directly to the battery with a switch; this is a big no no. If the smog station finds out they will consider this an emissions tamper, and should fail your car. Furthermore you can not get accepted into the CAP program with the radiator fan system running in this order. Again it will be considered a tamper. The CAP program does not accept vehicles which have had tampers related to the emissions system. The fan in your Toyota is party of the cooling system, and the cooling system is part of the emissions system.   One problem with running the fan manually... Battery load being which effects the engine computer's calculation on from the oxygen sensors inputs. In order words... By manually turning on the fan you are lowering the available voltage to the ECU which uses a reference 5 volts to calculate fuel delivery. You really want to have the fan operating only when necessary. If it seems it is necessary to run the fan at all times then your Toyota has an overheating problem which needs to be repaired before you take the smog test.   As far as the K & N filter... Switch to a basic paper filter. The K & N air filter, if too saturated, would absolutely restrict air flow specially if it is freshly oiled before the smog inspection. It will cause your Toyota to fail for high CO. Your best bet is to replace it with a regular air filter and re-take the smog test. If you were really close to passing, the paper air filter might do the trick. posted by SmogTips Support