Failed Emissions testing

Do not turn the engine off when you go in for the test. On many cars the readiness monitors run during each drive cycle and start over again each time, otherwise they would say "ready" because all the tests passed weeks ago. A problem could have developed in the meantime.

Once you stop and restart the engine and a new sequence of tests is initiated, there is always a long list of conditions that must be met for each test to run. Those might include a brief spurt of near wide-open-throttle, prolonged steady highway speed, coasting for a specific amount of time, and things like that. It is very likely some of those conditions wont be met on your way to the test station.

system not ready..meaning after clearing error code ,has to drive 50 to 100 miles for system to back ready. again.

My Honda failed the emission test. Each time I bring it in for testing the result indicates..NOT READY: HEATED O2,O2,CAT, EGR, EVAP. The guy at the test place told me to drive the car a few hundred miles and bring it back. which I did but the result is still the same even though I drove the car for over 1500 miles. I also check the fuses and all the fuses were good. The only thing I did before I brought it in for testing was replaced the orig gas cap with the one I bought from Autozone (not OEM) could this be the cause of the proble? Is there something I can do myself to make it pass the test?

hi Timothyvic,

Apart from the gas cap, I can't think of anything that would cause the system to be not ready for test yet.

My car is failing smog because it's running lean. Well maintained changed ozygen sensor, new spark plugs and wires, changed oil. Car runs smooth with no problems, no codes on computer showing. Dealer claims compression problems need valve job, smog techician said compression is good. Here are the numbers: CO2 15MPH 56 25MPH 14.1 25MPH 14.1/HC 15MPH 89 25MPH 87/CO 15MPH 1.39 25MPH 1.32/NO 15MPH 20 25MPH 25/Please advise.

As a smog tech, the numbers for the carbon dioxide seem to be incorrect, could you please restate them and the limits too. You seem to believe the condition is due to a lean mixture, please tell me your thoughts here.

CO2 15MPH 14.1 25MPH 14.1 I'm not seeing any limit numbers. Please see attachment

The mixture is actually too rich. Lambda is .9591. I would start with checking for an intake restriction and possibly a fuel pressure issue or perhaps an air mass sensor issue. There is a calculator available online for finding the lambda calculation at Smogsite.com, I use it to determine what the mixture is and for determining if the engine is in fuel control, yours is not. Mixture too rich is from fuel pressure too high, injection pulsewidth too long, intake restriction, Oxygen sensor sending incorrect information, engine coolant temp sender sending wrong input or it might be going into default because of ECT being ignored or disconnected (check wiring) Operation outside of proper fuel control can damage the cat after prolonged periods, let me know how you fare with this issue. ♥

I see you are in the 619 area code, so am I.

Thank you for your analysis. Any advice on where I can take my car without being taken?

I will check my sources and let you know straightaway.

My 1999 Honda Accord LX which I just purchased at an auction has failed emissions. As noted it only has 46,000 miles but it was stated to me that the vehicle was not driven for quite a while. What could be the problem and how do I rectify the problem?

The car was given a diagnostic testing prior to emissions testing and everything was fine.

Please help!

Hi msmanley,

We need to understand what is wrong and without the emission results, it would be looking for a needle in a haystack.

Being OBD-II vehicle, the check engine light will be on causing it to fail the emission test. What exactly written on the failed test. code numbers would greatly help to diagnose.

I resently bought a 1996 accord, its registered out of state, and I'm in california, so I need to get a smog for it to be registered. I took it to a smog guy and be told me that it wont pass because it has 3 monitors that are not ready (I dont know the codes but he said its the EVAC, o2, and cat converter monitors). He also explaned that the previous owner most likley cleared a check engine light before it was sold to me. They said i need to drive around for a while and the monitors will clear. After 90 miles, there was no change in the monitors, still had 3 not ready.. they also said the the EVAC sensor is independant, but the cat converter sensor wont reset unless the o2 clears and is working properly, like they are linked. The smog guy said I should get a new obd 2 sensor (upstream) and have him put it in, then drive around for a while again and see if some of the monitors reset and become ready for the smog. He said it should have reset by now so something is wrong. I also called a honda specialist and told him the situation, he said sometimes it takes weeks to reset the monitors depending on your driving habbits, he recommended that I keep driving it, not replace the sensor. and also, if the obd2 sensor isnt working properly, then the privious owner may not have reset a check engine light, right? because if monitors wont clear, the check engine light wont come on in the first place, right? Any information on this subject would be greatly appreciated, I'm on a budget and this is turning into a headache, I got conflicting information from the 2 different guys I spoke to.

So do have any odes set in the computer? If you do we need to start with that.Disconnecting the battery or clearing the codes will cause the monitors to be incomplete.

96 Accord LX with 115,000 miles. Failed CA Smog due to high CO% at 15mph. Was fine at 25mph. Original reading was 4.5 and the max allowed is .51
At advise of smog tech I cleaned the idle air control
(IAC) valve. The screen was very dirty. Took back for another smog check and this time CO% at 15mph was 1.04. Closer but still too high. Any other suggetions?

If you haven't done a tune-up in awhile, I would start there.

If that doesn't work I would take a close look at the oxygen sensor(s) and catalytic convertor.

I think it may be an ignition problem. Doesn't miss at idle or normal drive conditions. It barely misses a 1000 rpm to 2000 rpm it putts in that range. It looks like the whole distributor is brand new I take since the distributor is new the wires are new too. I change the plugs myself. However I have a 95 accord and the distributor are different just by the car being a year off its possible . The 95 has ign coil while the 94 doesn't which distributor is the right one. I'm the 6th own so someone both of these cars. My main concern is where do I start testing for high HC. It fails at idle . No dyno just 2 speed test in nv. 580 ppm while stay req is 220ppm

scan for codes and check fuelpressure first

Mil hasn't came on yet since I bought the car my guest is the previous owner reset the mil I'm still wait for a code. How can I check fuel pressure without any tools. I will start with the fuel pump because its buzzing unusual. It's a constant buzz that's not normal for this make n model

most auto parts rent the pressure gauge and /or some will do it for you

Which auto part store will do it for you in your home town?

Thx. I fixed it. The timing was way off. I did the timing change plugs and oil and pass smog flying colors. I guess when the previous owners put in the brand new distributor they didn't do the timing hence the miss at lo rpm

I have had my Honda for for 12 or more years. But my problem is possibly three fold. The brakes are spongy after the car starts to warm, but worse it fails smog there is a hissing noise near the firewall. After taking the car to two mechanics they could not find the vacuum leak. This repair could get expensive so I am doing some of the work myself. I was told that the brake booster could be the culprit. If so can the booster itself be repaired. Tried one from junk but it didn't work . Could it really cause both brake problems and failing smog. Lastly, I found a fuel injector that leaks sometimes. I will probably replace this myself. I do need some guidance in beginning this repair. Were should I start? Should it be the brake booster or the fuel injector?

You are most likely failing smog because of the vacuum leak. I would get the intake manifold and vacuum lines smoke tested. This will make it easy to find the vacuum leak. It could be the brake booster, or the vacuum line. There are many possibilities.

With regards to the spongy brake pedal, check your brake fluid level. If low, you may have a leak somewhere in the system.