scapegoat

I installed my borla catback thursday night.... sounds great. everything went easily enough.

This evening while pulling away from a light, as one normally would when there is traffic and rain... i hear a noise from the back, like a rattle... i figured maybe i didn't tighten a bolt enough. but i don't hear any rattles going over bumps so i figure it was something in my trunk.

i get to my location, buying masking tape for autox tomorrow, start up and leave. notice things sound a little... off. the car seems to accelerate fine, but i can feel something in the exhaust. at this point i figured the coupling fell off. no engine light comes on, so i assume the best (i suck at life )

i get home and park it, leave it running... walk around, check under it with a flash light... everything is attached...wtf... i rev it a little bit to see if i can hear where the issue may be coming from. i rev it to 1500-2000 and let it come back down, it hits 500, lights flicker a little and the car almost stalls... do this a few times with the same result.

I restart the car, all the issues go away. reving is fine, no loopy sounded idle.

still, no check engine light at any point.

any ideas? i would have assumed that if there was a serious issue the check engine light would have came on. I haven't been beating the car, to badly... worst i did was smoke the clutch trying to do a burn out (first rwd manual car) but that was only once.

I'm going to be setting up an appointment to take the car to the dealership on saturday, but i was wondering if anyone had any ideas... i highly doubt the catback exhaust would have had anything to do with this issue unless something did come loose. i'm going to double check everything tomorrow.

BL00DSH0T

As you stated it is highly unlikely that this is from the cat-back exhaust. Even if something came loose I don't see it effecting the way the car runs.
If there was any cylinders misfiring you would have a CEL.
Could just be a random issue, but something to watch for.

scapegoat

yeah... no CEL... i'm more worried about the rattle than anything at this point because it happened before the issue with the loopy exhaust sound. I'm going to get back under there and take another look at everything.

Where is the best place to jack it up from behind? the pumpkin seems like the only good choice under there :-/

FordEngineer

See https://mustangforums.com/forum/6447633-post18.html
I put a picture in that post from the service manual showing left points.

As for cylinder issues, you would get a MIL Telltale light (check engine) if you had a misfire condition (actually, it would flash on and off). If you have SYNC and checked the proper boxes while setting up Vehicle Health Report, you would also get a text message sent to you if your car detected this or any other 'red' condition.

If you noticed a rough idle or dimming lights, I'd have a look around the charging and fuel systems, even though that doesn't explain the rattling. Going back to SYNC, if you have vehicle health report set up, you may want to run one. It'll capture and report DTCs that don't illuminate the MIL telltale.

FordEngineer

Just another thought--exhaust pressures? Too high or too low? I would assume any product engineered for the '10 wouldn't cause this (especially one like you have), but just throwing it out there. The engine can 'learn' new calibration settings on its own every ignition cycle based on sensors placed throughout the powertrain (EGR and pressure included--but these can trip the MIL light if a value is way out of whack), but anyway, just my $0.02. I'm not a powertrain guy.

scapegoat

i'll set that up health report up tomorrow and see if anything comes up. the rattle has got to be from the catback... a bolt probably came loose. i'm just hoping that whatever the issue i experienced today is due to that.

as far as that image goes... are those circles referencing the jack points from the manual that you use the spare tire jack on? I've got a floor jack that i'm using. I've always assumed it was safe to use that on the rear diff, in fact thats what i read online.

thanks FE

FordEngineer

The circles are where Ford wants technicians at the dealership to lift from. I'm pretty sure the lift points they show there are for floor jacks/jack stands and 4-point hydraulic or screw lifts. I use a floor jack. The first picture on post https://mustangforums.com/forum/6502094-post25.html shows what I mean. I probably would have lifted from the rear diff too, but since I know what Ford recommends, I don't see harm in doing it their way.

tampa07gt

When I had my Pypes axle-backs installed the car pulled out of the shop fine. Then minutes later under throttle it seemed to make a noise and then miss. It happened twice. I pulled over and shut it off. No codes. I started it back up and it never happened again. I had just picked it up from the shop.

I think the CPU made an adjustment and all was well.

P.S. I have no background to make that assumption. It's just what I thought.

scapegoat

thanks tampa. seems to be the same issue here, cpu making adjustments.

issues are all gone. I did incorrectly mount the hanger of a muffler, hence the slight rattle. I unbolted everything and rebolted as tightly as i could. everything has been fine for a week now.

now to save up for those longtubes and shorty xpipe i been dreaming about

SMiller

If the ecm has a hard time relearning or adjusting then unplug the battery when you install the exhaust and a few times after, that way it will reset and relearn with the new exhaust, the best way to do it is to unhook the negative post at the end of the day and hook it back up the next day, then drive the car hard.