Mod problems?

[Guard5.0]

Out for a leisurely drive with the wife and the car suddenly felt like it lost some power. Pulled over to the side and it felt like the car was idling fine, popped the hood and looked for obvious things like a thrown belt on the SC but everything seemed in order. Oil pressure seems fine, no leaking fluids, etc. Got back in and tried some slow revs in neutral and there is basically a very retarded throttle response. The car will rev and is not missing but it takes forever for RPM's to build. Decide to take it home (30 miles) and while the car accelerates sloooowly it is running smooth and we maintain 70 on the highway and make it home fine. Almost like the drive by wire has malfunctioned or a vacuum line has come off. Check engine light is already on due to the headers which isn't in the initial Roush tune. Sound familiar to anyone with similar mods?

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[Tommy V]

Out for a leisurely drive with the wife and the car suddenly felt like it lost some power. Pulled over to the side and it felt like the car was idling fine, popped the hood and looked for obvious things like a thrown belt on the SC but everything seemed in order. Oil pressure seems fine, no leaking fluids, etc. Got back in and tried some slow revs in neutral and there is basically a very retarded throttle response. The car will rev and is not missing but it takes forever for RPM's to build. Decide to take it home (30 miles) and while the car accelerates sloooowly it is running smooth and we maintain 70 on the highway and make it home fine. Almost like the drive by wire has malfunctioned or a vacuum line has come off. Check engine light is already on due to the headers which isn't in the initial Roush tune. Sound familiar to anyone with similar mods?

I dont if u have acess to a real scan tool but thats wheir i would start.See if any other codes are in the pcm other than the ones due to the headers.Also check all ur boost connections.

 

[Guard5.0]

Update. I'm probably stupid. Never shut the car off when I pulled it over. Car has been sitting in the garage for an hour or so while we ate. just went out and checked all the wiring and vacuum hoses. All of it looked fine. Started the car and could immediately tell by the bark of the exhaust it was different. Took it down the road and everything is back to normal:frusty:. Could it be as simple as shutting it off? Does the car have a valet or nanny mode? Frustrating, but stupid of me not to shut it off and back on when it happened. Now to figure out why:headbonk:.

 

[ORANG50]

Why are you driving it around if you haven't updated the tune to account for the headers?

 

[Tyler2386]

Did you notice the cel flash? I guess it's possible the engine knocked and the pcm pulled timing or went into limp mode?

 

[Guard5.0]

Why are you driving it around if you haven't updated the tune to account for the headers?

Was waiting for the Brenspeed guys to get headers on their car which has the Roush SC. Sent Lund a message today and will likely have them tune it.

 

[Guard5.0]

Did you notice the cel flash? I guess it's possible the engine knocked and the pcm pulled timing or went into limp mode?

Didn't see a flash but that certainly feels like what happened.

 

[ORANG50]

Was waiting for the Brenspeed guys to get headers on their car which has the Roush SC. Sent Lund a message today and will likely have them tune it.

I would not recommend driving the car around if you have the headers installed, but no tune for it.

 

[Threebanger]

long tubes, a SC, and no tune is no bueno. You shouldn't be driving around with the CEL. If she can't get a good O2 reading, she can't give you the right AFR.

 

[Guard5.0]

Yea, I'm going to contact Lund to figure out my options, or maybe Beef since they do a lot of this stuff with Lund.

 

[Vile_the_Bastage]

Not sure if Mustangs do this (this is my first one), but in my two other built cars, running with a CEL on would put the car in limp mode to prevent damage. This could be what you are experiencing. One of my cars would return to normal operation after a restart but would go back into limp mode after a few miles.

I agree with the others, I wouldn't run that car with a CEL on. Also, when running forced induction, if you don't know what your AFR's are doing, you could be headed for Knock, Knock, Boom, Boom. Unlikely, but a possibility.

 

[Guard5.0]

All sounds reasonable, and probably true. Guess I need to talk to Beef, or directly with Lund and leave it parked till I can figure this out.

 

[Ehdrian]

"Have you tried powering it off and on again?"

[ame]

 

[Tyler2386]

Personally I don't think you'll hurt it driving without "tuning" for the headers. Most tunes for headers only make changes to turn off the CEL and some will make an adjustment to compensate for the O2 sensor moving back some. FWIW I spoke to a reputable tuner all of you guys are familiar with about this recently since I am doing the same thing. Just my .02.

 

[Guard5.0]

"Have you tried powering it off and on again?"

Hard for me to admit I worked in IT for 25 years and didn't think of simply turning it off and on. With a 10 second delay of course...

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