Sentra Spec-V Muffler

[jason51873]

Hey guys, quick question - I just got an 08 Spec-V about 3 weeks ago and got just a simple muffler for it. A day after the muffler was installed I get a check engine light. Any ideas or suggestions as to what I should do?

Thanks in advance for any help!
Modified by jason51873 at 9:32 AM 7/7/2008

[djtorello]

did you rehook up the ground wire?

[jason51873]

Shoot it was Jose Jiminez muffer shop lol I doubt they did, I'll get under there and look today after work. Thanks for the picture! Where exactly is that located?
Modified by jason51873 at 1:55 PM 7/7/2008

[djtorello]

If you look right next to the muffler mount there is a ground wire. Its there to prevent static electricity from screwing with your sensors, and actaully supposedly helps your exhaust flow better.

[jason51873]

Well looks like the ground wire is still hooked up. They welded it back on perfect so I guess that wasn't what was causing the problem. I stopped by the dealer and they said it might have been because of a loose gas cap so they reset the light. The cap is fine and the light came back on. I'm pretty sure its because of the new muffler.

Any other suggestions?

[nametakennow]

There's no way just a muffler could throw a code.

Get it read and find out what it is. The OBD system isn't just a light, after all.

[jason51873]

When I took it to the dealer they said it gave the same reading as if the gas cap was loose.

[nametakennow]

Then it's definitely not your muffler. That's an evap code.

You could have a bad gas cap. Get it pressure-tested.

[jason51873]

Then it's definitely not your muffler. That's an evap code.

You could have a bad gas cap. Get it pressure-tested.

Ok cool thank you very much for your help. I was kinda of hesitant about having the dealer do a full once over and then they come and say "oh its cuz of your aftermarket part" and try to make me pay some crazy amount of money to fix it.

But as long as I can be fairly certain its not the muffler I will let them go to battle with that light.

[nametakennow]

Aye, the evap system is purely between the gas cap, the fuel tank, and the evap canister. It just takes care of gasoline fumes and, therefore, doesn't share any connections with the exhaust. In fact, it'd be quite a bad idea for it to connect to the exhaust, KABOOOM!

If your dealer tells you it's the exhaust, tell them I'll wear a chicken suit for a week if they can prove it.

IMO you'd be better off with a full catback system anyway, though .

[jason51873]

Aye, the evap system is purely between the gas cap, the fuel tank, and the evap canister. It just takes care of gasoline fumes and, therefore, doesn't share any connections with the exhaust. In fact, it'd be quite a bad idea for it to connect to the exhaust, KABOOOM!

If your dealer tells you it's the exhaust, tell them I'll wear a chicken suit for a week if they can prove it.

IMO you'd be better off with a full catback system anyway, though .

Man are you a PRO or what!!??

Using the ignition / gas peddle pressing technique I was able to retrieve the error code:

P0442 Evaporative Emission Control System Leak Detected (small leak)

[nametakennow]

You're under warranty. Tell them to fix it for free.

Like I said, it's probably a bad gas cap, but it could be a bad evap canister purge valve or some sort of tiny leak in a fitting/line/etc. Whatever it is, it's Nissan's problem now!

I'm not a pro, I've just dealt with a million of these codes. I'm fairly certain Nissan hasn't made a good gas cap in over a decade - every Nissan throws an evap code at some point. You'd think at some point it'd be more expensive to replace them than to make a better one.

[djtorello]

IMO you'd be better off with a full catback system anyway, though .

Only thing i dont agree with. The B16 se-r and spec already have a great exhaust system. People who went to the 2.5" pipe from the 2.25" lost alot of power. My suggestion is to keep the stock exhaust piping, Use a better resonator then the stocker, the stocker is huge and quite heavy.

[nametakennow]

Only thing i dont agree with. The B16 se-r and spec already have a great exhaust system. People who went to the 2.5" pipe from the 2.25" lost alot of power. My suggestion is to keep the stock exhaust piping, Use a better resonator then the stocker, the stocker is huge and quite heavy.

I'd love to see the dynos that prove this. I'd also like to see what happens when a header and cams come out.

The idea that a car loses torque (I've never seen anyone claim a loss in peak power from larger piping, only zero or minor gains) because of larger piping is questionable, but even if we accept that, a catback alone definitely can't cause those losses. The change in flow from a catback by itself is fairly minimal, and, in fact, most of the minor gain in power is associated with the smoother design (i.e. fewer/less extreme bends) and a less restrictive resonator and muffler, hence why most people only gain a couple of hp, if that, from a catback. Once a header is added, a catback is necessary to realize the full gain.

[jason51873]

Yea, the muffler I got is a Dynomax Super Turbo. They are really nice sounding mufflers and I was able to get one that matched up perfect because it was 2.25" and the piping offset matched the stock positions.

I'm not really into showmanship so I even kept the stock tip.

Oh BTW - my car is at the dealership now and they are saying they don't know what to do about the Check Engine Light LOL!!

They said that they could not find any leaks and now they have to contact Nissan to see if there is a computer update they can do!

[nametakennow]

Nice. I'm surprised they didn't just change out the gas cap, clear the code, and hope that is the actual problem. That's what they've done to me most of the time.

There is an outside chance that it's a computer issue, though.

[nismo4life11]

hey guys im having a sensor code come up the 2nd sensor blah blah one for the pre-cat but it doesnt show up all the time, it comes and goes as if it has a mind of its own. I just got my new exhaust installed headers cat and cat back, i dont have the exhaust grounded right now and the light is off (for the time being) could this code be coming up because im not running a ground and the sensors getting some sorta shock now and then???

[jason51873]

hey guys im having a sensor code come up the 2nd sensor blah blah one for the pre-cat but it doesnt show up all the time, it comes and goes as if it has a mind of its own. I just got my new exhaust installed headers cat and cat back, i dont have the exhaust grounded right now and the light is off (for the time being) could this code be coming up because im not running a ground and the sensors getting some sorta shock now and then???

Yea djtorello was thinking that might be a problem with mine at first. But my was connected so that was ruled out.

UPDATE: The dealer finally located my issue, the actual sensor was installed wrong and had a leak - they fixed the sensor and now "you should be good to go" says the service tech.

[nametakennow]

jason - Sounds good!

nismo - Put the ground wire on the exhaust and see what happens. However, it sounds like you have a header and didn't relocate/sim/etc the second O2 sensor. The light may be coming on and off because the O2 sensor's readings are going to vary on startup vs after driving awhile and such.

I guess I should just ask, what did you do with the second O2 sensor?

[nismo4life11]

I have the spark defouler thing done on the second o2 and the code comes up when ever it feels like it, it doesnt come up on start up it just does it when ever but its off right now so im gunna do the ground wire and hope that works. Also if this helps any it seems to do it when we are going to get thunderstorms and during one too.


Modified by nismo4life11 at 4:29 PM 7/11/2008

[nametakennow]

Could be from the increase in charge in the surrounding air. Check up on that ground wire.