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Discussion Starter #1
I have a Startech exhaust on my 14 sport SC and I have notice lately when I am in neutral or rolling in neutral and I rev the exhaust the car feels like it is backfiring right before you hear the lovely popping sound from the exhaust. I don't know if backfiring is the right word for what is actually going on. The exhaust pops at 4000 rpm so when I am in park or neutral or rolling neutral and I am reving the engine, I feel like the car kicks forward slightly between 3500 - 4000 rpm when I quickly rev it to 4000. Can anyone shine some light on what you think is happening. This doesn't seem to be normal at all and never occurred with my stock exhaust. When I first start the car for the day and it warms up it revs through all the rpms smoothly for awhile like the way it supposed to.

Thank you
 

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Was the exhaust retorqued after you drove it for a while? Could it be an air leak that shows up once exhaust heats up and expands?
 

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Have you set it so that the exhaust flap is open in neutral?
The Startech system is supposed to only be 'open' in sports mode (so when S is selected). If you rev in neutral or while rolling, that may be it....

You can set the system so that it is open all the time (i've done that), probably better, there really is no use fro quiet mode lol.
 

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More importantly, are you really driving around and neutral revving an automatic thinking it sounds cool. Anyone that would actually appreciate that exhaust is going to laugh when they hear you having to let it rev down to put it back in gear.
 

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More importantly, are you really driving around and neutral revving an automatic thinking it sounds cool. Anyone that would actually appreciate that exhaust is going to laugh when they hear you having to let it rev down to put it back in gear.
LMAO??


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Discussion Starter #6
Have you set it so that the exhaust flap is open in neutral?
The Startech system is supposed to only be 'open' in sports mode (so when S is selected). If you rev in neutral or while rolling, that may be it....

You can set the system so that it is open all the time (i've done that), probably better, there really is no use fro quiet mode lol.
The valves are overrided to stay open all the time via the paddle shifters. I only wish it could pop and crackle more but that's ok I love it otherwise. It's not an SVR :)

I'm wounderig if my rev issues is a sensor going bad. Possibly a O2 sensor. The reason I say that is because I see no issues when the car first starts up and of course I only test it when the engine warms. It would rev through all rpms as usual but later in the day when I test it again it would start to reach up again (not every time though)
 

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You cannot gauge any problem from a free rev of an engine. Weird sounds and crackles are of no value unless it's happening while under load then you can determine there's a problem. The computer isn't programmed with advanced logic to sound cooler when not moving.
 

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The ECU also isn't programmed to deal with the changes in back pressure from changing an exhaust system. Basic fueling will slowly change with the long term changes in O2 readings but when you are free revving any engine you are likely to experience unexpected over fueling leading to burbles and crackles. Some car makers such as Ford and Dodge intentionally over fuel their performance production cars for this effect. I seriously doubt LR is part of that trend. Let's not forget that free revving of auto transmissions is a pretty major foul. As noted above there is absolutely nothing to be gained by sitting in park or neutral yellow lining your rig for the sake of "diagnostics".
 
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