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When I bought my C5 I was told it had long tube headers and a borla catback exhaust. It sounds absolutely amazing and unfortunately did not bother about asking if it would pass emissions. I talked with people and found out that the headers could pass if it got tuned but it absolutely needed cats. I jacked up the car and found these which obviously aren’t the original cats but I am unsure if they were deleted or if these are high flow cats. I want to think they are are high flow cats because it doesn’t sound obnoxious. I need help in order to pass emissions but also don’t want to lose the beautiful sound.
Last edited by Nick_Vergara; Jun 8, 2021 at 10:33 PM.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
most likely those are high flow cats and should pass a visual inspection so as long as you don't have a cel and your readiness monitors are set you should be good... it depends on your state but in tx you are allowed 2 "not ready" on pre 01 cars and 01+ only one "not ready" and still pass
Yeah I would just drive it until your monitors either pass or set the CEL. Then you'll know whether or not you need to worry about it.
Here is the drive cycle needed to pass readiness for your cat.
Yeah I have attempted these drive cycles on numerous occasions and still see the not ready codes which is why I’m unsure if the high flow cats are being problematic.
Do you know if it has been tuned? I know tuning can prevent the MIL from coming on. Maybe that means it won't ever be "ready"? You'd think the AIR system would be ready too if you've been driving it for a couple days. I had a bad air pump and it would set MIL every few key cycles.
Do you know if it has been tuned? I know tuning can prevent the MIL from coming on. Maybe that means it won't ever be "ready"? You'd think the AIR system would be ready too if you've been driving it for a couple days. I had a bad air pump and it would set MIL every few key cycles.
Unfortunately I have no idea if it has been tuned, the only info I have is that it has long tube headers and a borla catback exhaust. I might have to get it tuned and see if that helps, because I have driven the car at least 450 miles since I got it and done at least 5 driving cycles.
Unfortunately I have no idea if it has been tuned, the only info I have is that it has long tube headers and a borla catback exhaust. I might have to get it tuned and see if that helps, because I have driven the car at least 450 miles since I got it and done at least 5 driving cycles.
You need to get yourself a scanner to see what the O2 sensors are doing. If the rear O2 sensors aren't working or are disconnected the air injection check never become ready. Read the DIC codes to see if you have any. Looks like you need to get it checked and get a tune to eliminate the not readys. Are you in NJ?
You need to get yourself a scanner to see what the O2 sensors are doing. If the rear O2 sensors aren't working or are disconnected the air injection check never become ready. Read the DIC codes to see if you have any. Looks like you need to get it checked and get a tune to eliminate the not readys. Are you in NJ?
Yes I do live in New Jersey, I will try to check if the rear 02 sensors are even there.
I had my rear O2's being a problem and I had a tuner just delete them from the system. If it is the rear ones you might be able to get that done. Mine is now on a collector car insurance though so I don't need to worry about emissions anymore.
Yes I do live in New Jersey, I will try to check if the rear 02 sensors are even there.
You can see the clips for the rear O2 sensor wires in your first pic and there are no wires going through them. If your check engine light is staying off without rear O2 sensors, I think it's safe to say someone tuned them out and that's why it never passes readiness. They probably did the same thing with the AIR pump.
You can see the clips for the rear O2 sensor wires in your first pic and there are no wires going through them. If your check engine light is staying off without rear O2 sensors, I think it's safe to say someone tuned them out and that's why it never passes readiness. They probably did the same thing with the AIR pump.
So they did not do a good job on the tune. You can bring it to someone like east cost supercharging in plumstead. They can tell you what needs to be done. Your lucky they didn't fail you for visual inspection, you would have been really screwed.
You can see the clips for the rear O2 sensor wires in your first pic and there are no wires going through them. If your check engine light is staying off without rear O2 sensors, I think it's safe to say someone tuned them out and that's why it never passes readiness. They probably did the same thing with the AIR pump.
Yea my check engine light is not on so I guess you would be right about it having a tune already. I have been in contact with East Coast Supercharging so just waiting to hear back from them. I really hope this can be resolved with a good tune.
So they did not do a good job on the tune. You can bring it to someone like east cost supercharging in plumstead. They can tell you what needs to be done. Your lucky they didn't fail you for visual inspection, you would have been really screwed.
Yea I’m currently talking to them because I live in Central NJ so they’re like 30 minutes out which is pretty convenient. But I’m new to emission inspections because my old car didn’t need them, would having the high flows fail the visual and them be a pain to switch them out? Or why do you say I’d be screwed?
Yea I’m currently talking to them because I live in Central NJ so they’re like 30 minutes out which is pretty convenient. But I’m new to emission inspections because my old car didn’t need them, would having the high flows fail the visual and them be a pain to switch them out? Or why do you say I’d be screwed?
If you search the forum. There was a guy that recently failed inspection in NJ because he had headers. Once you fail for that there's no way to pass unless you get some kind of exemption or return to stock. NJ law appears not to allow headers and the cats must be in the stock location. That guy was the first one that I heard that got rejected. That's what I meant by your lucky. Don't know if they are starting to enforce this or it was just that one inspector being a dick.
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
Originally Posted by Nick_Vergara
Yea I’m currently talking to them because I live in Central NJ so they’re like 30 minutes out which is pretty convenient. But I’m new to emission inspections because my old car didn’t need them, would having the high flows fail the visual and them be a pain to switch them out? Or why do you say I’d be screwed?
no, it shouldn't fail a visual... they are only looking to see that cats are installed on the car, not what's inside them... now if your state requires you to pass a sniffer test you would most likely be screwed
All they do in NJ these days is plug into OBD and read the codes, nobody opened the hood, I don't think they did any visual, definitely no sniffer or dyno anymore. Pretty sure you need to get the O2 sensor extension and hook it up, then get it tuned.
Doing an header install whenever I get some free time actually but I just got my car inspected stock so I won't have to deal with this for another 2 years. Definitely keeping the stock manifold/down-pipe around just in case.
Ps. Eff the government.
Last edited by LSgoBRRR; Jun 10, 2021 at 07:05 AM.
All they do in NJ these days is plug into OBD and read the codes, nobody opened the hood, I don't think they did any visual, definitely no sniffer or dyno anymore. Pretty sure you need to get the O2 sensor extension and hook it up, then get it tuned.
Doing an header install whenever I get some free time actually but I just got my car inspected stock so I won't have to deal with this for another 2 years. Definitely keeping the stock manifold/down-pipe around just in case.
Ps. Eff the government.
They do not do a visual most of the times. I have seen them look under the car for catalytic converters. If the inspector see's that you have no pup cats he can fail you because no OEM catalytic converters can be removed and they must be in the stock location. Just read the NJ law on emission compliance. I bet most inspectors do not know about the pup cat thing on the C5 and Z06's don't have them. Maybe we need a lawyer to interpret the law for us. https://www.corvetteforum.com/forums...he-cycles.html see post #14 he failed for visual inspection.
Last edited by C5MSG2004Vert; Jun 10, 2021 at 08:22 AM.
I have an 01 Z so I unfortunately have pre-cats (thanks California you *****s)... which is half the reason for doing the headers but I doubt the people that work at the inspection station know that, if the computer is happy they are happy. Hopefully I can depend on the laziness/corruptibility of the system, if not I'll have to make a ritual out of swapping my headers in and out every couple of years.
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