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Intermittent loss of power with exhaust noise and no codes

sczamun

Member
U.S. Air Force Veteran
Messages
13
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Location
Indianapolis
#1
Hello, I have a 2019 Fiesta ST with 86,000 miles. As far as I can tell, it is stock and I've put about 3000 miles on it. New sparkplugs and the old ones looked good.

I have a power drop when accelerating WOT. The only thing I've noticed that happens along with the power drop is a loud "sshhhh" noise coming from the exhaust. I mean, if you ever shushed someone, it is an extremely accurate representation. It could be coming from in the exhaust or it might just be it resonating. I believe that its more likely the former since it sounds like its coming from the muffler.

If the car is started and it does it once, it'll usually do it for the rest of the time the car is on. If the car is started and it doesn't do it, it'll drive excellent for the rest of the time. I believe the diverter valve is also louder when the car is working correctly.

I now have a Cobb Accessport. My first instinct is that it is an issue with boost/wastegate. However, on the stock tune, I get ~19 psi. On a stage 1 Dizzy 93/E30 tune, I get ~24.50 psi. On the stock/E30 tune, there are only positive ignition corrections and the 93 only has occasional negative corrections that quickly recover.

I looked at the intercooler hoses during my last oil change, and they all seem to be on tight.

What do you think I should monitor or look for?
 


OP
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sczamun

Member
U.S. Air Force Veteran
Messages
13
Likes
3
Location
Indianapolis
Thread Starter #2
I would also like to add that by powerdrop, I mean it still accelerates. Just feels gutless.
 




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