Tips to pass smog in California. My first post. I'm a smog tech.
The smog check consists of 3 parts visual, functional, and tailpipe emissions. Fail any part and you won't pass the test.
FWD and RWD cars are required to be tested on the dyno. Vehicles are tested on a dyno at 15MPH and then at 25MPH to put a load on the engine. AWD is exempt from the dyno and use the two speed idle test. The engine is revved to about 2500RPM tested and then at idle. Two speed idle test's require the EGR to be tested functionally by applying vacuum to the EGR while the engine in running and the motor should stumble or stall. If not EGR is faulty and you will fail.
Functional: tests performed are timing check(eclipse excluded timing N/A), gas cap pressure test, check engine light, ECU, and EGR(awd only).
OBD1
IF pre 96(OBD1) all you have to worry about is if your check engine light is on. If on, unplug your battery for a few minutes and plug back in right before smog, light should go off and as long as it doesn't turn back on during the test your all good.
OBD2
96 and up(OBD2)cars are more troublesome you cant just unplug your battery. You also can't just erase check engine codes and lights. Smog checks requires the smog machine to communicate with the ECU thru OBD2 port. Most cars will pass this functional test as long as you still have your stock ECU and you don't have any check engine codes(no CAT?) and if you haven't reset the ECU by unplugging the battery(you need to have you emissions components to be monitered explained later).
Also for awd card they test the EGR so you need to have that as well. If front wheel drive they dont test it but they check to see if it is there and the ECU moniters it . Other cars get tested for timing but since ours isn't adjustable we get to slide on that.
Visual inspection for emission components consist of checking for PCV, EGR, fuel leaks, CAT, O2 sensors, air pump(eclipse don't have), EVAP(charcoal canister), TAC hose(eclipse don't have), disconnected vacuum hoses or sensors.
Ignition systems are ok to modify as long the centrifugal or vacuum advance mechanisms aren't tampered with(ours are computer controlled so no worries there). After market intake manifolds are ok as long as all the original provisions for the oem emission controls are there. EX: EGR, air pump, vacuum lines,PCV etc... Intercoolers are accteptable but only for oem turbochargers.
As for your visuals related to modified parts, any part that affects emissions in any way is a fail without a carb sticker. You basically fail for most mods. EX: injectors, cams, nos, fuel pump, FPR, AFC, after market Turbo, FMIC for after market turbo, intercooler piping, BOV that doesn't recirculate, downpipe(especially with no cat), exhaust piping, headers, Boost controller, any piggyback controller, throttle body, etc.....
Acceptable parts are Ignition, intake manifold, exhaust muffler, intake cone, radiator, tranny, differential, body kits, spoilers, speakers, battery, etc....
Don't worry too much about it all tho because the technician isn't gonna worry about most of that stuff because he wont even know that it is there. Don't ask don't tell, if asked LIE. As long as it's not noticeable the tech probably wont notice either.
The thing to worry about the most is your intercooler piping, header, and intake piping and anything else that is obvious when you crack your hood. Cone filters are OK but intake piping and changing the MAF in any way is not. PCVs are a part of the visual and so are any loose vacuum lines so they need to be connected.
Turbos: Cant be modified, but if you have an internal wastegate you are OK with your turbo long as your turbo looks stock and you have your stock manifold. If you have your heatshield to block the view of the turbo as much as you can. If you have an external gate hide it. If you have a polished turbo your outta luck, unless the smog tech just doesn't notice.
Upper and lower intercooler piping needs to be hidden because those are illegal and lead the tech to find your FMIC(if so equipped) which is also illegal on a after market turbo. If you could hide your piping or put back the stock pipes the technician wouldn't even trip off of your front mount. With a stock looking turbo like a 16G or 18G you don't have to worry cause the tech will think it's stock so your FMIC is OK.Recirculationg your after market BOV is legal, if you are venting which isn't allowed then recirculate it or put back your stock BOV.
THE MOST IMPORTANT THING TO REMEMBER ABOUT VISUAL IS THAT IT IS 100% UP TO THE TECHNICIAN WHETHER OR NOT TO PASS YOU FOR VISUAL. Don't tell him anything about your fuel pump, AFC, injectors or anything at all. Try to keep all your parts looking stock, paint things black, and nothing shiny.
Emissions: Without a CAT your car won't pass visual and it sure as hell won't pass emissions. You also have to have a cat so you won't have a check engine code. Also a new cat will always work better than a used one.
You need to have all your emissions components being monitered by the ECU. Which means if you unplugged your battery for a while or if you reset your trouble codes recently your ECU will be erased. You then must drive you car around and put the car thur its drive cycle to have your ECU monitered. This is very hard to do. You will need to drive at a slow and steady pace at 30 up to 65 mph without stepping on the brake. You will need to do this for at least one whole tank of gas or more. Just drive really steady whenever you drive and make sure you hop on the freeway too.
As for you emissions you can fail for high HC(fuel), CO(carbon monoxide), and NOx(Oxide of nitrogen). These are the only three you can fail for. If your CO or HC is high you could lean out a bit with your afc. If your NOx is high you should richen it up with an afc or other contorller. You can do this after your test, most test onlys allow a free retest if you fail. So adjust your AFC then go back. Also hide the AFC and sssshhhh.
HC and CO are usually high due to unburned fuel so you lean it out. NOx is high when it get's too hot in the combustion chamber usually from being lean. Richen it up and Nox will go down for sure. Fuel will also help cool it down.
DON'T RICHEN TOO MUCH OR YOU WILL MAKE HC AND CO FAIL AND LEANING IT OUT TOO MUCH WILL MAKE NOx GO UP. FIND A GOOD BALANCE.
Advancing your timing will increase NOx but will reduce HC AND CO and retarding your timeing will reduce NOx and bring up your HC and CO. FIND A GOOD BALANCE.
These are just tips for a failed emissions sometime it still won't be enough and further diagnosis is gonna be required.
Make sure your car is good and warmed up, Plugs are good, O2 sensors are good, no vacuum leaks, clean air filter, clean fuel filter, clean injectors,stock boost is best, also the best time to go is when it is really busy, the technician is more likely to skip something and just trying to speed though the tests,and that's pretty much it. GOOD LUCK
The smog check consists of 3 parts visual, functional, and tailpipe emissions. Fail any part and you won't pass the test.
FWD and RWD cars are required to be tested on the dyno. Vehicles are tested on a dyno at 15MPH and then at 25MPH to put a load on the engine. AWD is exempt from the dyno and use the two speed idle test. The engine is revved to about 2500RPM tested and then at idle. Two speed idle test's require the EGR to be tested functionally by applying vacuum to the EGR while the engine in running and the motor should stumble or stall. If not EGR is faulty and you will fail.
Functional: tests performed are timing check(eclipse excluded timing N/A), gas cap pressure test, check engine light, ECU, and EGR(awd only).
OBD1
IF pre 96(OBD1) all you have to worry about is if your check engine light is on. If on, unplug your battery for a few minutes and plug back in right before smog, light should go off and as long as it doesn't turn back on during the test your all good.
OBD2
96 and up(OBD2)cars are more troublesome you cant just unplug your battery. You also can't just erase check engine codes and lights. Smog checks requires the smog machine to communicate with the ECU thru OBD2 port. Most cars will pass this functional test as long as you still have your stock ECU and you don't have any check engine codes(no CAT?) and if you haven't reset the ECU by unplugging the battery(you need to have you emissions components to be monitered explained later).
Also for awd card they test the EGR so you need to have that as well. If front wheel drive they dont test it but they check to see if it is there and the ECU moniters it . Other cars get tested for timing but since ours isn't adjustable we get to slide on that.
Visual inspection for emission components consist of checking for PCV, EGR, fuel leaks, CAT, O2 sensors, air pump(eclipse don't have), EVAP(charcoal canister), TAC hose(eclipse don't have), disconnected vacuum hoses or sensors.
Ignition systems are ok to modify as long the centrifugal or vacuum advance mechanisms aren't tampered with(ours are computer controlled so no worries there). After market intake manifolds are ok as long as all the original provisions for the oem emission controls are there. EX: EGR, air pump, vacuum lines,PCV etc... Intercoolers are accteptable but only for oem turbochargers.
As for your visuals related to modified parts, any part that affects emissions in any way is a fail without a carb sticker. You basically fail for most mods. EX: injectors, cams, nos, fuel pump, FPR, AFC, after market Turbo, FMIC for after market turbo, intercooler piping, BOV that doesn't recirculate, downpipe(especially with no cat), exhaust piping, headers, Boost controller, any piggyback controller, throttle body, etc.....
Acceptable parts are Ignition, intake manifold, exhaust muffler, intake cone, radiator, tranny, differential, body kits, spoilers, speakers, battery, etc....
Don't worry too much about it all tho because the technician isn't gonna worry about most of that stuff because he wont even know that it is there. Don't ask don't tell, if asked LIE. As long as it's not noticeable the tech probably wont notice either.
The thing to worry about the most is your intercooler piping, header, and intake piping and anything else that is obvious when you crack your hood. Cone filters are OK but intake piping and changing the MAF in any way is not. PCVs are a part of the visual and so are any loose vacuum lines so they need to be connected.
Turbos: Cant be modified, but if you have an internal wastegate you are OK with your turbo long as your turbo looks stock and you have your stock manifold. If you have your heatshield to block the view of the turbo as much as you can. If you have an external gate hide it. If you have a polished turbo your outta luck, unless the smog tech just doesn't notice.
Upper and lower intercooler piping needs to be hidden because those are illegal and lead the tech to find your FMIC(if so equipped) which is also illegal on a after market turbo. If you could hide your piping or put back the stock pipes the technician wouldn't even trip off of your front mount. With a stock looking turbo like a 16G or 18G you don't have to worry cause the tech will think it's stock so your FMIC is OK.Recirculationg your after market BOV is legal, if you are venting which isn't allowed then recirculate it or put back your stock BOV.
THE MOST IMPORTANT THING TO REMEMBER ABOUT VISUAL IS THAT IT IS 100% UP TO THE TECHNICIAN WHETHER OR NOT TO PASS YOU FOR VISUAL. Don't tell him anything about your fuel pump, AFC, injectors or anything at all. Try to keep all your parts looking stock, paint things black, and nothing shiny.
Emissions: Without a CAT your car won't pass visual and it sure as hell won't pass emissions. You also have to have a cat so you won't have a check engine code. Also a new cat will always work better than a used one.
You need to have all your emissions components being monitered by the ECU. Which means if you unplugged your battery for a while or if you reset your trouble codes recently your ECU will be erased. You then must drive you car around and put the car thur its drive cycle to have your ECU monitered. This is very hard to do. You will need to drive at a slow and steady pace at 30 up to 65 mph without stepping on the brake. You will need to do this for at least one whole tank of gas or more. Just drive really steady whenever you drive and make sure you hop on the freeway too.
As for you emissions you can fail for high HC(fuel), CO(carbon monoxide), and NOx(Oxide of nitrogen). These are the only three you can fail for. If your CO or HC is high you could lean out a bit with your afc. If your NOx is high you should richen it up with an afc or other contorller. You can do this after your test, most test onlys allow a free retest if you fail. So adjust your AFC then go back. Also hide the AFC and sssshhhh.
HC and CO are usually high due to unburned fuel so you lean it out. NOx is high when it get's too hot in the combustion chamber usually from being lean. Richen it up and Nox will go down for sure. Fuel will also help cool it down.
DON'T RICHEN TOO MUCH OR YOU WILL MAKE HC AND CO FAIL AND LEANING IT OUT TOO MUCH WILL MAKE NOx GO UP. FIND A GOOD BALANCE.
Advancing your timing will increase NOx but will reduce HC AND CO and retarding your timeing will reduce NOx and bring up your HC and CO. FIND A GOOD BALANCE.
These are just tips for a failed emissions sometime it still won't be enough and further diagnosis is gonna be required.
Make sure your car is good and warmed up, Plugs are good, O2 sensors are good, no vacuum leaks, clean air filter, clean fuel filter, clean injectors,stock boost is best, also the best time to go is when it is really busy, the technician is more likely to skip something and just trying to speed though the tests,and that's pretty much it. GOOD LUCK
