Car wont pass smog..... need some help!!

[Cabriolet]

that's an air leak.
PMing you my #
i can help u fix that sunday

[ol89]

im having same problem.. but was reading on other forum that it might be bad intake boot or hoses

[Wasefi]

Ok R3Vers, I tried smogging my car a 3rd time and still I failed at 15mph due to high levels of NOx. A fellow r3v member helped me out with air leaks on my intake boot and the car ran much smoother and got better gas mileage but still no passing smog. Anybody else that can help me out??

[rhE-30]

Get you self some carb cleaner spray and spray in areas that may leak air. Listen for idle changes, the area you are spraying would be where the leak is. One not so obvious spot, and where my leak was, was the fuel injector O-rings.

[Cabriolet]

Bummer, i was hoping we got it patched enough. you will need a smoke test for sure. to find the rest of the leaks

[///digitalme]

Get a new cat a magnaflow costs 180installed. I had the same problem last year until I just bought a new cat and it passed

[Wasefi]

Has anyone tried topping off the fuel with some E85 to help lower NOx? I heard of multiple people trying it with their cars and passing smog here in CA.

[wilholl]

Get a new cat a magnaflow costs 180installed. I had the same problem last year until I just bought a new cat and it passed

Seafoam treatment will help with high NOx if you haven't done that already.
But seriously, a new cat will fix almost all of it.

[smooth]

Has anyone tried topping off the fuel with some E85 to help lower NOx? I heard of multiple people trying it with their cars and passing smog here in CA.

have you been fighting this issue for the past year or are you asking because it's time for you to get smogged again?

[Wasefi]

have you been fighting this issue for the past year or are you asking because it's time for you to get smogged again?

Yeah been having this issue since august of last year. Starting to miss my car a lot and want to complete it.

[nrubenstein]

Has anyone tried topping off the fuel with some E85 to help lower NOx? I heard of multiple people trying it with their cars and passing smog here in CA.

Ethanol raises nox and lowers everything else unless you have a very high proportion of alcohol.

The solution to your problem is to borrow a good OEM cat from someone. I'll bet that you've got a shitty magnaflow or similar from when the cat was replaced. I had a 220x (not a type or exaggeration) drop in NOx when I sucked it up and put an OE cat behind my old S50 instead of the shitty magnaflow.

You could try doing a citric acid clean on your existing cat as well. It's very effective at degunking cats without damaging them. (I can't say affirmatively that it improves performance, but it certainly gets an impressive amount of crap out.)

[efficient]

Ethanol raises nox and lowers everything else unless you have a very high proportion of alcohol.

The solution to your problem is to borrow a good OEM cat from someone. I'll bet that you've got a shitty magnaflow or similar from when the cat was replaced. I had a 220x (not a type or exaggeration) drop in NOx when I sucked it up and put an OE cat behind my old S50 instead of the shitty magnaflow.

You could try doing a citric acid clean on your existing cat as well. It's very effective at degunking cats without damaging them. (I can't say affirmatively that it improves performance, but it certainly gets an impressive amount of crap out.)

How do you clean it with citric acid?

[Navarone]

A quick google search says that you soak the cat in a hot water and citric acid solution for about 6 hours. The amount of citric acid looks like a pound per gallon, but that seems pretty excessive, and 6 hours? I bet it would work better with some agitation like a sonic bath.

You should follow the tried and true directions. I like to fiddle around so I would mix the hot water and citric acid and pour it through the cat over and over, or fill it half full and cap the ends and shake it for a few mins and then dump the water, wash rinse repeat with new mix until the water comes out pretty clear.

Citric acid is a pretty mild acid too, I wonder how phosphoric acid would work. You can find it a brewers and hydroponic supply stores being used as a PH down. Citric acid can be found in animal supply places and some food places called sour salt. Cola is pretty acidic, or just crush up a pallet of vitamin C tablets and use that!

[THEhomelessONE]

Try the coolant temp sensor, only like $10. Beat the hell out of it before you bring it in, don't let em shut the car off or let it idle too long. My stock cat on the 318is passed smog even with over 500k and a chip lol.

[Wasefi]

Try the coolant temp sensor, only like $10. Beat the hell out of it before you bring it in, don't let em shut the car off or let it idle too long. My stock cat on the 318is passed smog even with over 500k and a chip lol.

Will have to try this out this weekend, probably a good sign of why my temperature gauge jumps around.