So..... The shifter has new bushings now and they replaced the plugs and O2 sensors.

They couldn't get the aftermarket catless pipes to seal correctly on the passenger side which was possibly what lead to the O2 sensor fouling and causing issues.

I found a stock catted downpipe/H-Pipe which sealed much better and also quieted down the rowdy Borla Atak mufflers.

But.... the mechanic said it's still running funny and needs a tune. Apparently the O2 sensor on Bank 2 isn't reading so the fuel Trims are off. The sensor is new and wiring is fine so he thinks it's a PCM issue or bad tune.

Ideas?

 

I Would Have Them Do a Smoke Test & Check For Vacuum Leaks. Need To Rule That Out!

Could Also Swap Out One Of Those Other Tunes on Your Programmer. See If Your Trims Change. After The Change You Will Need To Go Through a Drive Cycle & Stabilize Everything!

Does That Different Intake Use Charge Plates? Those Can Be Problematic as Well. Also Sometimes When They are Eliminated The Original Wiring To The Charge Plates Will Get Poorly Placed & Ground Out I Times if Memory Serves. Just Throwing That Out There!

Is Car Setting Any Codes??

I was Just Reading an Old Thread The Other Day Where The Guy Kept Having Odd Issues With His Car and The BBK T/B Ended Up Being The Issue. After Replacing With Stock One Issues Went Away. Just Putting That Out There as A Possible!

Is it Running Lean or Rich?

Also While Many Sources Say That The 2005-2010 GT'S Have No PCV Valve That is Incorrect it is Integral to the L/H Valve Cover. See Pdf. A Bad or Broken Valve Will Cause Fuel Mixture Issues. I Guess Nobody Bothered to Research Very Far Out in Google Land Cause Most Say they Don't Have One! I Gotta Believe the Factory Shop Manual!



Kc

 

I'll have to check tomorrow. It was up in the air when I stopped down to check. I do know that it was running lean previously.

Given that they didn't even cam the car, I'm wondering why they bothered with the Ford Racing intake and BBK 62mm throttle body.

 

Gotcha! See Added Edits After Quote For a Bit More Ammo!

KC

 

After All those Changes Such As The Cats & 02's The PCM Should Be Reset or 5 Min Batt Disconnect and Drive Cycle Performed To Know Everything Has Reset Would Be a Good Idea. Here is The OBD Drive Cycle Procedure. Same To Be Said if Tune Changed. I Had Mentioned Earlier But Had Not Made Process Available. This Is What You Would Go Through To Be Emission Testing Ready if Car Was To Be Tested. Scanner Would Indicate if Any Components Were Not Up To Snuff at This Point.

BTMO

KC

 

Looks like the charge plates could be an issue... this looks like the intake I have

https://www.americanmuscle.com/ford-...-manifold.html

 

I Think The One I Was Talking About Had The Wiring Pinched Between Intake & Head Possibly. It Was grounding Out at Times. Been Awhile. Should Be Able To Find Loose Harness at Rear or Engine. Just Need To Make Sure Its Sealed Up, Not Pinched & Tucked Away!

See C-191 on PDF.

Kc

 

I'm starting to think I bought someone's mess..... I hesitated too. I wasn't sure I wanted someone's undocumented "upgrades".

 

Did you ever figure out if the car has an aftermarket tune installed, and if so who wrote that tune?

I think you need a good tuner to work with. The best one I know, is "Lito" who is known as the "3V whisperer" and works remotely by e-mail using datalogs. He will need to know what modifications the car has, to write a proper tune for it. He might be able to figure out some of the mods or issues through data-logging, but probably at extra cost. You can contact him at support@tudyno.com if interested.

I'm pretty sure the Boss intake does not have charge motion plates and that is (partly) why it needs a tune adjustment.

If the O2 sensor really is bad, or the wiring is bad, or for some other reason O2 sensor is not giving valid readings, that will be a problem that cannot be corrected in the tune. Not sure if he can detect bad PCM through datalogging.

It kinda sounds like the prior owner didn't really know what they were doing and threw some mods at the car because they sounded cool in the ads.

 

If the Ford racing manifold does not have charge motion plates? Then yes, your Mustang would require an aftermarket calibration tune... My apologies for not thinking about that sooner...

 

I got the message saying that cars work was finished today so I went down there. Apparently Bank to oxygen sensor upstream was not turning on but they were not getting a code for it for some reason. So I plugged in that Bama tuner and just decided to apply one of the two Tunes to see if it would wake up the pcm. Apparently that did the trick because now it is turning on and the check engine light is gone although the fuel trims between the Left Bank and right Bank are little off from each other. A little further than what he would like to see so he is going to switch out one of the two 02 sensors to see if it's possibly defective.

Side note: with the stock cats back in place, it REALLY tones down the rowdy Borla Ataks out back....

Just hoping a faulty O2 sensor is the issue now....

 

Thanks for that info... yes... i think i acquired someones pieces parts mess. i applied one of the tunes today just for kicks and the bank 1 o2 sensors heater turned on and the code was gone. My mechanic plugged his big tablet in and the fuel ratios from left and right were not as close together as he would like to see although the car seemed to be running smooth. He's going to switch out the O2 sensors to rule a faulty one out. And then I will go and get a tune that is very specific for this car

 

that is very strange, I have no explanation for that -- no idea why the front O2 sensor heater would have been turned off in the previous tune .... it is common to turn off the rear O2's but that does not affect how the car runs (rear O2's are used only to confirm that the catalytic converters are working, for emissions compliance purposes)

 

my mechanic couldn't figure out why it wasn't throwing a code for that either. The car was running fine even though his tablet registered that that O2 sensor heater was turned off or just reading zero. It might have been a glitch in the tune or something.

All I know is that they took the car for the drive today a couple times and it is running very smooth. They had their test equipment plugged in while the car was driving and the fuel trims are within range of each other. One side seems a little laggier than the other but he said they're not off enough to really worry about at this point. He said drive it for a week or two and we will retest it at that time to see if maybe the car just needed to wake up a little bit.

the only big difference that was made was getting rid of the catless downpipes and putting the factory downpipe and cats back in place up front. It still has the borla Atak Cat-Back after that. My assumption is adding a little bit of back pressure or restriction confused the fuel trims just a hair because the tune was set up for no cats. Maybe that will just have to be dialed in.

I still plan to ditch the 4.10 gears and go back to 3.55s...

Then i plan on having a dyno guy actually fine tune the car from there

thank you to everyone who has replied and given advice thus far. As techie as I can be at times, I never really dug into computer-related anything when it came to cars. I'm A Little More content dealing with carburetors, heads, headers and all of that jazz like when I was a kid.

 

if you can't find a good dyno guy nearby, remote tuning by datalog (by Lito) is the next best thing ... maybe better in some cases, depending on the skill and experience of your local dyno guy

 

If the last person who tuned your car was attempting to prevent the check engine light from displaying, all he had to do was just turn off the rear 02 sensors in the tune... There was no need to mess around with the front/upstream 02 sensors whatsoever... Therefore I'm completely stumped as to what he was attempting to accomplish there... Anyhow, I'm glad that by plugging in the Bama programmer and then re-flashing the PCM with one of their preloaded tunes was able to turn the bank to oxygen sensor upstream back on, thus getting rid of the check engine light...

I think your mechanic is doing the right thing by switching out one of the 02 sensors to find if one of them is defective, if neither are found to be defective, then I would suggest that a tune adjustment may be required for getting the fuel trims between the left and right banks back in sync, no pun intended...LOL. Meanwhile, I can totally relate with putting the stock cats back in place to tone down the Borla ATAKs, as I also had my stock cats reinstalled to tone down my Borla ATAKs... They were just way too loud for my liking when briefly running straight pipe with no cats... I was also concerned with the possibility of failing visual inspection here in the Commonwealth Of Pennsylvania as well... At any rate, the Borla ATAKs provide more than enough volume even with the stock cats still in place, at least IMHO...

From my understanding, once the 02 sensors have been reactivated/turned back on, it takes approximately 50-100 miles of drive cycle before the 02 sensor heaters are able to fully reactivate and able to read again... Therefore, I would follow your mechanics advice by driving your vehicle for about a week or so to ensure the 02 sensor heaters are hot enough to be able to read once again...
Otherwise, as I mentioned above, you may require an adjustment in the tune for correcting the left and right fuel bank trims, but I feel pretty confident that your 02 sensors just need a drive cycle between 50-100 miles of driving in order to fully reactivate the 02 sensor heaters...

I can also fully relate with ditching the 4:10 gears and reinstalling the stock 3:55 gears, as I also ditched the 4:10's as well, as they were just horrible for street driving and especially when highway driving on the interstate at cruising speeds when in 5th gear, not to mention that when running a supercharged application, anything above 3:73 gears on a street driven vehicle is really nothing more than just overkill, to begin with...

Therefore, I believe your making the right choice by ditching the 4:10 gears in favor of having your stock 3:55 gears reinstalled...