Can't seem to find a distinction anywhere, I know most aftermarket plenums are 96-04, but was thinking stock ones were different and am concerned I bought a 96-98 plenum for a couple reasons. One being that my afr instantly pegs at 10.0 at WOT (at least the richest my AEM will read, probably richer I'm guessing), with a tune that was more responsive before I touched the stock one that was on the car when I bought it.

I'll get a picture of mine if they are different just to make sure. Thanks

That's gotta be something else.... Why is your car running pig rich?? Even for most f/i that's pretty rich, and n/a that's a real problem. Are you getting any dtc's (probably generated by upstream O2 readings) that would back up what your afr says?

Unless maybe it is an incorrect reading?

Anyway, if anything a larger plenum/tb would cause it to run a little leaner, theoretically. And I haven't set the two down side by side to compare, but I would bet $1 that the plenum/tb on all 96-04's remained unchanged.

What kind of A/F ratio gauge are you using? Where and how is the sensor placed in the exhaust?

Thanks for the response. Long story short, I've had an ongoing struggle getting my car to run right ever since trying an aftermarket TB and 2 different plenums (with an updated tune from Bama). After a ton of troubleshooting, I was able to determine the plenum being the likely issue, but by that time my stock one had gotten thrown out So I have a low mile stock one from Ebay that looks clean and correct, and shortly afterwards installed my AEM. However I'm guessing if there's any difference between my original stock plenum and this one, since I've reverted to that original tune, and seemingly the only difference should be the "stock" plenums.

I am using an AEM Uego 30-4100 with the Bosch sensor. I have the sensor in the back passenger O2 of my O/R Prochamber, which I understand can cause long-term condensation issues for the sensor. But so far it seems to be working reasonably, at idle warmed up, the reading bounces around the mid 14 area, and bounces around that area or a little richer in light driving. But the instant you give it WOT, it pegs 10 and stays there while you're on it.


I'm on the fence between seeing if Bama will give me a slightly leaner version of my current tune (I realize that's a liability risk for them) or saying screw it and running to the local dyno. Thanks for the help and suggestions, any advice is appreciated.

Just something to chew on....

Many, many people are running aftermarket tb's and plenums without issue - or at least without the issue you're having. Admittedly my short term is crap, but I honestly cannot think of one similar issue probably ever on this forum or the other one I lurk at. Just for curiousity's sake though, what were you running?

But... There have been several stories around here recently regarding issues with Bama tuning. I don't know what the hell's going on down there, maybe they've had some personnel changes, whatever. But for at least the last 3-5 months "issues" of various nature have been almost common or frequent. They do write a lot of tunes, probably more than any of the competition currently, and I get that nobody's perfect or exempt from having a bad day, but 99% of the time I come across a thread about a tuning issue the name Bama is in there. Some people have had luck in resolving them, others haven't and subsequently moved on to somewhere else for tuning.

So based on the above, it is my opinion that the likely culprit to all of this is the tune. Of course definitely give them a shot or two at correcting the problem - speak with any of the AM reps here and see how they want to do it, but I suggest that you do a little datalogging with your handheld device and send the file to them so they can accurately see what's going on and therefore help them to make corrections that will actually work.

I agree with SoCal on that. I'm in no way trying to bash on Bama nor AM because I have bought A LOT of stuff from AM. They have been very good with me on pretty much every order I have made. I have easily spent a few grand with them and going to be making another purchase of parts here soon. This is just my honest opinion. I would go to a dyno with a very good reputable tuner. Yeah you may pay a couple hundred more but this tune is specifically for your car and is going to be more spot on. Of course I understand the budget deal and most people would agree for a minor bolt on car Bama is a good choice. I have just seen and heard way to many things lately like SoCal stated. Every company has things here and there but hopefully "if this is something on Bama" they will get it straight and make things right.

Thanks. A bit I probably should've mentioned earlier. When I initially put on the 70 mm TB and plenum (1st was Stack Racing), I went through and datalogged through my tuner and had them revise the tunes. I went through that process 5 times, and each time I noticed no difference in my recently acquired bog below 3k. Even between race/performance/street, they all seemed the same which I didn't understand. I even went to the expense of buying an Accufab plenum and to little surprise now, it did the exact same thing. Btw, all my tunes have been for 91 octane, and I run only BP 91 in my car for consistency.

I got frustrated and gave up on the new tunes shortly after that, and pursued trying to get back my pre-tb-plenum street tune that pulled great. Bama re-sent me that tune supposedly, but maybe it wasn't and someone messed up.

Anyways, now that I have an actual a/f reading that I have a decent amount of confidence in, I'm going to let Bama see what they can do again. I wouldn't think I should have to dyno-tune a near-stock GT just to get it in the ballpark, but am not against doing what is needed to get it right.

Have you tried reinstalling the stock tune? Try that n' see if anything changes.

redriderjf87,

Did you ever get a hold of the Bama Team about the most recent issue? Either way, I was able to find your info in our system a moment ago and escalated it over to one of my best guys. I want to make sure this issue is solved ASAP for you!

To help us straighten this out, could you give me some more info about what you're experiencing? Is the issue just the Air/Fuel or is there more to it? The more details you can provide the better.

You can expect a call from a Bama Specialists within the next 24 business hours with an update. They'll continue to work with you until a solution is found. If you need assistance with anything else, please let me know!

Shane

I'm actually not sure how to do that, if I would have had to back it up, or if it stays on the tuner to restore. And I'm actually not sure if there was a tune on the car when I bought it or what, it would do the same kind of low rpm bog, which was fixed when I first tried the Bama. I still wouldn't mind trying stock though just for comparison.

Thanks Shane, I just got an email earlier today to follow-up on and give you guys a call. I will try to give them a call tomorrow for sure otherwise. Btw, the issue seems to be a bog that's 3k and below when I give it close to WOT (and pegs reading rich). No noises, pinging, or weird behavior otherwise. At 3k is where it seems to quickly get better, but I will see if the A/F stays pegged rich or gets any better at high rpm's.

Update, at least for my "original" working Bama tune, I figured out part of my problem. When I put the tune back to my original working tune, I pulled some timing from earlier troubleshooting my plenum tune, and re-loading the original ones did not reset the parameters. The car does not peg rich now, but consistently reads 10.6 AFR with stock plenum at WOT, so I'm guessing there is room for improvement. At this point, I'm going to decide which tb/plenum combo I want to move forward with, and will give Bama a call as soon as I can. Am currently in the process of buying a house and do not have the car accessible daily, so I will get with them and post updates as I get them. Thanks again Shane/Socal/Fordman.