Check Enginge Light Flashing/ Hissing (Air) Sound

[lincoln361]

Ok guys, I have a problem with my L99 Supercharger. I just got done replacing the plugs with BR7EF and installing a RX Phenolic spacer. I'm planning on running Nitrous but I cant seem to get over this hump. Once the install was done.

I would stomp on the gas pedal and the car would hesitate, vibrate a little and my AFR would go to 10.9 and I would get all the stabilitrak, traction control lights and such. I would go to auto zone to get the code read but the check engine light would go away and my afr would go back to normal. I did notice that when I went home and leave the car running and pop the hood that I could hear a hissing sound or some type of air leak. I did notice that I put the belt tensioner kind of tight, not sure if this could cause this or not, I doubt it though. No nitrous was running when all this occurred. I did tap into the purple TPS wire and Tach wire but the nothing was programed with the window switch and don't have it armed.

[Tampa Tuning]

if its just flashing, you probably are misfiring

[lincoln361]

Could the plugs have something to do with that? It didnt do that before before the install

[lincoln361]

Well before I could even add the nitrous into the vehicle. I add a check engine light.

It only comes on when when i stomp on the gas pedal. I don't know what it could be. The check engine light comes on with all the other lights and my afr reads 10.0. Once i let off the gas it drives normal with slight hesitation. I could know what it could be. I got a spark plug tester and they all show good. I only tapped into the TPS and Tach wire and the window switch is not activated at all. So i doubt its that. I do hear a hissing sound and cant seem to find where it is coming from. I tried soap n water and didn't come up with nothing. Any advice? I changed out the spark plugs with BR7EF so when i run the nos, don't know if that would make a change in the way it acts or not. People say on here a flashing engine light is a misfire. Any input would be great

[TommyTheCat]

A flashing CEL is always a misfire, it flashes to inform you the misfire is bad enough to damage or melt the catalytic converters.

Check the fuel trims during misfires to see if they are rich or lean, if they are lean and you are hearing that vacuum noise I'd suspect a vacuum problem but with all the mods it is harder to diagnose

You said you replaced the spark plugs, those are NGKs? I've never heard of a spark plug tester unless you are just testing for spark which is not going to tell you if that is a misfire or not and is primarily used to diagnose if the plugs are indeed getting the spark from the ignition control module rather than testing the plugs themselves. I would try replacing with the old plugs if still available or just with whatever you used to have in there before the new ones

If these are the racing plugs which are not adjustable I always have problems with those. One guy with an RSX Type S came in because he messed up his timing chain job, which he thought would fix his problem. Halfway through the timing job he gave up and brought everything to us in pieces. After we fixed everything he messed up (which was a lot, so many extra parts disassembled for no reason and he even took off the front brakes and loosened the axle nuts, drained the tranny fluid for some reason without telling us... no dipsticks on manuals either smart guy) the CEL was still on. We tried some original plugs instead of the expensive performance plugs he put in and the problem was fixed like that, $20 repair that he caused with a tune up and then wasted well over a thousand bucks on unneeded parts. Just my two cents on those plugs, but I'm not sure if that's what you used

Start simple with your diagnostics or you'll regret it later.

What is your AFR at normally

[lincoln361]

Originally Posted by TommyTheCat

A flashing CEL is always a misfire, it flashes to inform you the misfire is bad enough to damage or melt the catalytic converters.

Check the fuel trims during misfires to see if they are rich or lean, if they are lean and you are hearing that vacuum noise I'd suspect a vacuum problem but with all the mods it is harder to diagnose

You said you replaced the spark plugs, those are NGKs? I've never heard of a spark plug tester unless you are just testing for spark which is not going to tell you if that is a misfire or not and is primarily used to diagnose if the plugs are indeed getting the spark from the ignition control module rather than testing the plugs themselves. I would try replacing with the old plugs if still available or just with whatever you used to have in there before the new ones

If these are the racing plugs which are not adjustable I always have problems with those. One guy with an RSX Type S came in because he messed up his timing chain job, which he thought would fix his problem. Halfway through the timing job he gave up and brought everything to us in pieces. After we fixed everything he messed up (which was a lot, so many extra parts disassembled for no reason and he even took off the front brakes and loosened the axle nuts, drained the tranny fluid for some reason without telling us... no dipsticks on manuals either smart guy) the CEL was still on. We tried some original plugs instead of the expensive performance plugs he put in and the problem was fixed like that, $20 repair that he caused with a tune up and then wasted well over a thousand bucks on unneeded parts. Just my two cents on those plugs, but I'm not sure if that's what you used

Start simple with your diagnostics or you'll regret it later.

What is your AFR at normally

From the sounds of everything that im reading. It looks like a misfire of some sort. I do not have any cats.

My afr goes to 10.0 when i stomp the gas pedal with the check engne light coming on and off and getting the other lights on as well with some backfiring and when i get home and open the hood, i can hear like air releasing of some sort. Maybe a compression test need to be done? Im pretty sure we secured the tvs2300 correctly and torqued all the bolts.

Yes i replaced my NGK TR6 plugs with BR7EF plugs gapped at .28. The old plugs still looked good too when i replaced them. Yes the tester i bought, you would touch the plug wire and it would illuminate. I figured since i illuminated the plug was good. SMH NOOB

My normal afr showed 14.7 on my gauge and still shows that now at idle but when i stomp on the gas it goes to 10.0. I really don't know what else to do. My tuner sent me this

I would pull the valve covers and look for a broken valve spring or bent pushrod. If you have new plugs and wires, you could be getting a misfire from bad valve control. That would make it flash.


Patrick Guerra

[TommyTheCat]

Originally Posted by lincoln361

From the sounds of everything that im reading. It looks like a misfire of some sort. I do not have any cats.

My afr goes to 10.0 when i stomp the gas pedal with the check engne light coming on and off and getting the other lights on as well with some backfiring and when i get home and open the hood, i can hear like air releasing of some sort. Maybe a compression test need to be done? Im pretty sure we secured the tvs2300 correctly and torqued all the bolts.

Yes i replaced my NGK TR6 plugs with BR7EF plugs gapped at .28. The old plugs still looked good too when i replaced them. Yes the tester i bought, you would touch the plug wire and it would illuminate. I figured since i illuminated the plug was good. SMH NOOB

My normal afr showed 14.7 on my gauge and still shows that now at idle but when i stomp on the gas it goes to 10.0. I really don't know what else to do. My tuner sent me this

I would pull the valve covers and look for a broken valve spring or bent pushrod. If you have new plugs and wires, you could be getting a misfire from bad valve control. That would make it flash.


Patrick Guerra

The computer is programmed to flash the CEL for bad misfires that can damage the cat, removing the cats and the tune does not remove the programming so it still 100% a misfire problem, that much I can guarantee you.

[lincoln361]

He only emailed me the last paragraph. I dont know if it is a pushrod or a valve spring. Car sounds fine other than the hissing sound. What is the bad valve control? Where do i find that in the vehicle. I tapped into the purple tps wire and blue/white wire for the tach wire. Could that be a problem

[TommyTheCat]

Originally Posted by lincoln361

He only emailed me the last paragraph. I dont know if it is a pushrod or a valve spring. Car sounds fine other than the hissing sound. What is the bad valve control? Where do i find that in the vehicle. I tapped into the purple tps wire and blue/white wire for the tach wire. Could that be a problem

I woudln't suspect anything with the TPS.

Start simple like I said before you go tearing stuff apart. I doubt you would have internal problems in the engine if it happened immediately after the recent mods. Starting with replacing the spark plugs again would be the easiest thing to do, and do a compression test at the same time. I'm not sure about the hissing sound, you should upload a video of that

[lincoln361]

Originally Posted by TommyTheCat

I woudln't suspect anything with the TPS.

Start simple like I said before you go tearing stuff apart. I doubt you would have internal problems in the engine if it happened immediately after the recent mods. Starting with replacing the spark plugs again would be the easiest thing to do, and do a compression test at the same time. I'm not sure about the hissing sound, you should upload a video of that

Sounds like a plan. I will check the spark plugs and install the old ones. I know the old ones are not gapped. I was reading a article about vacuum leaks and alot of it that i read pertains to the hissing part sound from my car. By any chance, do you think that me tapping into the tach wire would have any effect to this matter as well?

[lincoln361]

Originally Posted by TommyTheCat

I woudln't suspect anything with the TPS.

Start simple like I said before you go tearing stuff apart. I doubt you would have internal problems in the engine if it happened immediately after the recent mods. Starting with replacing the spark plugs again would be the easiest thing to do, and do a compression test at the same time. I'm not sure about the hissing sound, you should upload a video of that

Changed out the spark plugs and still the same thing. Car hesitating and misfiring. Check engine light will flash than a couple of seconds later it will go away. If i keep the speeds at 70 the car drives ok. But once i press the gas it starts up again. The hissing sound was coming from a hose. Replaced it and it went away

[TommyTheCat]

Just retrace your steps. If it started as soon as you did stuff to the car it is probably not a coincidence.

[lincoln361]

Originally Posted by TommyTheCat

Just retrace your steps. If it started as soon as you did stuff to the car it is probably not a coincidence.

took it to the dealer and it came to be the tach wire that I had tapped into. It was not picking up a strong signal and causing everything to haywire. So next question is, where do I tap into for the nos mini progressive controller. I tapped into that one but was it the right one? Also, where is the TPS Signal wire, I tapped into the purple one, is that the right one? Thanks in advance and thanks for all the pointers before

[TommyTheCat]

Originally Posted by lincoln361

took it to the dealer and it came to be the tach wire that I had tapped into. It was not picking up a strong signal and causing everything to haywire. So next question is, where do I tap into for the nos mini progressive controller. I tapped into that one but was it the right one? Also, where is the TPS Signal wire, I tapped into the purple one, is that the right one? Thanks in advance and thanks for all the pointers before

Sorry I don't have a supercharger or 6.2L so I can't be certain exactly, but maybe this will help you out


GN=Green
Pu=Purple
L-BU=Light bLUE
TN=Tan
WH/BK=White w/ black stripe
GY=Gray
D-GN=Dark Green
BN=Brown

etc etc