Failed Emissions in my 98 corolla

[HybridSquirrel]

I don't know who made your 98' Corolla, but it doesn't have an EGR valve. NOx, or OXIDES of NITROGEN (not the other way around), is typically created when the internal combustion temperature reaches 2500 degrees F (or exceed it). This condition can be caused by many things, carbon build-up, lean running condition, ECT malfunctioning, etc... (anything that makes the engine runs hotter).

Scan a picture of your Vehicle Inspection Report and post it here, I may be able to tell you a bit better about what it's doing.

And yes, you can reset the CEL by disconnecting the battery terminals (for good measures, touch the negative and positive cables to discharge any capacitors in the system). The reasons why you'd fail for the CEL is because it's an automatic fail for the visual inspection, regardless of the cause. As long as the CEL is not on at the time of inspection, and you have no more than two emission related continuous monitors incomplete, you can pass provided that your emission equipments are functioning properly.

From the numbers you posted, I can't decipher what is what, as HC and NOx are measured in ppm (parts per million) and the other 3 gases are measured by percentage, you also didn't post the O2 percentage as that is also a good indicator of how your engine is performing, correlating to the other four gases.

Pics or BAN!

haha alright ill scan them, my haynes repair manual says i have an egr, i took it to the shop i used to work at and me and my friend took it out. im looking at the manual right now and it says only the cali-model cars have egrs...so maybe my car is from cali?

 

[SSSnail]

haha alright ill scan them, my haynes repair manual says i have an egr, i took it to the shop i used to work at and me and my friend took it out. im looking at the manual right now and it says only the cali-model cars have egrs...so maybe my car is from cali?

If your engine is 1.8L with the timing chain, it definitely doesn't have one. My daily beater is a 98' Corolla, and I'm from Cali and it doesn't have an EGR valve, nor have I ever seen a 98' Corolla with an EGR valve.

Oh, btw, disconnecting the battery and touching the cables will also clear the codes.

 

[brblx]

What the fuck? How is turning the light switch on and disconnecting the battery even related? That's completely absurd! So absurd, that I've got to try it! The reason I know that disconnecting the battery doesn't reset codes is not only have I been told, but every vehicle I've worked on, OBD-I or OBD-II while may hide the check engine light, but when you ask if it has any codes, it always remembers them with the only way of getting rid of the code is to reset it by either using a tool or shorting two pins.

if you knew a single goddamn thing about cars, you'd know that you have to either have the negative (or positive, but neg is recommended) disconnected for a significant period of time, or bring it over and touch it to the positive. this is to discharge any parts (capacitors) that may still be holding a charge. this is generally called a 'hard reset.'

 

[fleabag]

if you knew a single goddamn thing about cars, you'd know that you have to either have the negative (or positive, but neg is recommended) disconnected for a significant period of time, or bring it over and touch it to the positive. this is to discharge any parts (capacitors) that may still be holding a charge. this is generally called a 'hard reset.'

That STILL doesn't explain their leaving the lights on crap they were talking about...

 

[HybridSquirrel]

If your engine is 1.8L with the timing chain, it definitely doesn't have one. My daily beater is a 98' Corolla, and I'm from Cali and it doesn't have an EGR valve, nor have I ever seen a 98' Corolla with an EGR valve.

Oh, btw, disconnecting the battery and touching the cables will also clear the codes.

here are the set pictures, I just went and disconnected the battery and ran the lights for 10 minutes like jlee suggested. when i drive to the liq store later i will see if the check engine light comes back on

http://img199.imageshack.us/img199/1967/001ut.jpg

http://img691.imageshack.us/img691/8830/002ui.jpg

 

[gaidensensei]

I would recommend that you erase out some of the info on your car, just for the sake that you don't want some of that stuff appearing in searches at a later date..

Basically anyone working with areas the government knows your online identity right now.

 

[SSSnail]

here are the set pictures, I just went and disconnected the battery and ran the lights for 10 minutes like jlee suggested. when i drive to the liq store later i will see if the check engine light comes back on

http://img199.imageshack.us/img199/1967/001ut.jpg

http://img691.imageshack.us/img691/8830/002ui.jpg

Holy crap old machine is old, as it only reads four gases. My apologies as I'm not very familiar with this prehistoric museum piece.

Regardless, looks like you barely fail NOx, so here are a few things you can do to help: 1) Run higher octane gas for one or two tanks (since you're not failing HC or CO, and the engine is not a high compression engine, higher octane can help lower the combustion temperature) 2) Check for vacuum leaks and if your air filter is clean, a severely dirty air filter can lead to a lean condition

Leaving the lights on is unnecessary as you simply just disconnect both terminals and touch them for a few seconds would do the trick. After having done that, drive on the freeway for about 50 miles and most monitors would complete.

 

[brblx]

those repeated NOx spikes make it look like this more an issue of the engine just not running well.

how long has it been since you've had a tune-up? plugs, cap and rotor, fuel filter, et al?

 

[HybridSquirrel]

those repeated NOx spikes make it look like this more an issue of the engine just not running well.

how long has it been since you've had a tune-up? plugs, cap and rotor, fuel filter, et al?

less than 3k miles ago.

Holy crap old machine is old, as it only reads four gases. My apologies as I'm not very familiar with this prehistoric museum piece.

Regardless, looks like you barely fail NOx, so here are a few things you can do to help: 1) Run higher octane gas for one or two tanks (since you're not failing HC or CO, and the engine is not a high compression engine, higher octane can help lower the combustion temperature) 2) Check for vacuum leaks and if your air filter is clean, a severely dirty air filter can lead to a lean condition

Leaving the lights on is unnecessary as you simply just disconnect both terminals and touch them for a few seconds would do the trick. After having done that, drive on the freeway for about 50 miles and most monitors would complete.

yeah they have a pretty ghetto setup there, he had to manually crank the paper through the printer as it printed it out. i usually run 91 octane, and my air filter is pretty clean but ill clean it up some more and take it back on monday if the CEL doesn't come back on. How do i check for vacuum leaks?

 

[brblx]

smoke machine. or can o' smoke. you hook it up to an vacuum port and look for leaks.

if it's not setting a CEL for fuel trim, you probably don't have a vac leak.

 

[SSSnail]

less than 3k miles ago.

yeah they have a pretty ghetto setup there, he had to manually crank the paper through the printer as it printed it out. i usually run 91 octane, and my air filter is pretty clean but ill clean it up some more and take it back on monday if the CEL doesn't come back on. How do i check for vacuum leaks?

If you don't have a test set, you can check around the engine for all the vacuum hoses to make sure they're not cracked or disconnected. Usually there is a vacuum diagram affixed to your hood, follow that. Check the usual, breather hoses, PCV, brake booster, etc... Listen for sucking air sound. Baring that, you will have to take it to a competent mechanic shop to diagnose further. Typically though, the catalytic converter on these cars fail at around this age as they're noto

 

[HybridSquirrel]

well idk what the CEL was for because i dont have a scanner...if it comes back ill go somewhere and borrow a scanner and find out what codes its throwing. for a while it was throwing a P0420 which is a bad o2 sensor, but i replaced the up and downstream ones and it went away.

edit: i dont have the vacuum hose diagram on the hood because i got into an accident and dont have to factory hood. but the haynse manual has one. i think a new cat on my car will run me ~500 dollars because they have to cut my old one out of my exhaust...since the genius who did my custom exhaust welded everything on.

 

[SSSnail]

well idk what the CEL was for because i dont have a scanner...if it comes back ill go somewhere and borrow a scanner and find out what codes its throwing. for a while it was throwing a P0420 which is a bad o2 sensor, but i replaced the up and downstream ones and it went away.

Did it fail after you replaced the O2 sensors or before?

 

[HybridSquirrel]

Did it fail after you replaced the O2 sensors or before?

after, i replaced them last winter to pass emissions last year.

 

[SSSnail]

wtf... forums gone wild.

Try de-carbon your engine if it won't cost you too much.

 

[HybridSquirrel]

EDIT: i did de-carb it last night, thats when the CEL came on.

 

[SSSnail]

EDIT: i did de-carb it last night, thats when the CEL came on.

So you took the head cover off, cleaned your valves, pistons, etc...?

 

[HybridSquirrel]

So you took the head cover off, cleaned your valves, pistons, etc...?

nah, i ran mopar de-carb cleaner through the intake, soaked it for 2 hours, smoked out my apartment complex and drove around for a while.

 

[SSSnail]

nah, i ran mopar de-carb cleaner through the intake, soaked it for 2 hours, smoked out my apartment complex and drove around for a while.

That doesn't really do anything, and if it did, probably fouled up your O2 sensors again. The only way to properly de-carbon an engine is to take it apart and clean it.

 

[HybridSquirrel]

That doesn't really do anything, and if it did, probably fouled up your O2 sensors again. The only way to properly de-carbon an engine is to take it apart and clean it.

eh, the cel hasnt come back on yet today, and i drove around a while so we'll see. ive used it before and we used it all the time when i still worked for jeep

 

[SSSnail]

eh, the cel hasnt come back on yet today, and i drove around a while so we'll see. ive used it before and we used it all the time when i still worked for jeep

Well, I'm one to believe that there's nothing chemically that can really completely break down the carbon deposit so it can pass harmlessly through the combustion process and passing through the catalytic converter to be freed on the other side. So all the smoke that you usually see is just that, smoke and mirror, or in this case, pollutants created by introducing a foreign substance into the combustion process that's typically HC, N2 and O2, a lot of pressure and a spark.

 

[HybridSquirrel]

Well, I'm one to believe that there's nothing chemically that can really completely break down the carbon deposit so it can pass harmlessly through the combustion process and passing through the catalytic converter to be freed on the other side. So all the smoke that you usually see is just that, smoke and mirror, or in this case, pollutants created by introducing a foreign substance into the combustion process that's typically HC, N2 and O2, a lot of pressure and a spark.

well even if it works just a little bit so i can get the .1 points to pass emissions for this year, i dont have to worry about it for another 2 years.

 

[HybridSquirrel]

ended up having to get a cat replaced. but now its making this noise

http://www.youtube.com/watch?v=VF9yGQ_t6KA

my theory is that because the new cat is bigger than my old, its hitting the stabilizer bar (at least i think thats what it is) underneath the car as seen here (the pic is taken with my old cat on)

if i take it back to the place i got it put on, do you think they will replace it with a smaller one if i go complain enough?