Just recently I had a tune done with my O2's accidently reversed, meaning front and back were swapped. How would this effect my AFR's during a custom tune? One thing I did notice during the tune was that my car was drastically effected by the heat which is not a common thing with my car and it's cooling system.

The last time I ran I made 18 runs in 3 hours with my numbers varying slightly if anything. This time around I made 5 runs and my crap was all over the place. I really couldn't understand what was going but we worked with it and still ended up with some good gains. It just took a lot more cool down time...and dyno time . It was 10 degrees warmer but still....

Even before the tune my car had a rough idle which I assumed was a product of the header install. After the tune I still had the rough idle and the first thing I did was take into my dealership the moment I got home. After a few hours of diagnosing the problem he found that my O2's were swapped around. I'm thinking with the main O2's wired to the back my ECU was thinking it was lean and started adding fuel which would explain my erratic dyno runs. Any thoughts on this? Since the problem was fixed my car does seem like it's running richer, slight gas smells I never had before. My gas mileage also dropped around town and on the freeway, not by much but still a drop. I'm having my car dynode and possibly re-tuned due to these circumstances.

Please give your opinion on the outcome of having my car tuned with O2's swapped. If any other questions need to be answer please feel free to ask.

 

I think you have already figured out the problem. Given what you know now, I would make sure your tuner blesses you continuing to drive the car. Smelling gas from the rear on your setup could be BAD. Best case, you will black out your engine internals so get it dealt with asap IMO.

BTW, headers should NOT make your car idle rough. In our cars, only cams bring that on. The headers should easily be tuned smooth.

Edit: I would be more concerned with timing than AFRs. You say gains were got. How?

 

I've already contacted pc and they will be re-tuning my car. This is a unfortunate mistake but **** happens, I understand this. Just to clarify, the gas smell is during startup only. Obviously I won't be racing or driving my car much until my car is retuned.

At no point would I ever believe Jeremy would put my car in harms way just to make power. If I thought this for a moment they wouldn't be touching my car.

So, yes you believe my tune could be highly effcted with the O2's swapped?

 

Do you means wire swaped or just the rear sensors in the front? If you were reading after the cat, then I think you would be reading leaner(cats doing their job) and then may end up a little richer going back to reading pre-cat. So , if anything your tune could have been set up on the rich side, as it was reading leaner after the cat..

Again, this depends if the wires were swaped or just sensors. Most cars, front and rear sensors are the same..

 

I know how you are, so no need to defend PC. I guess my point was that certain parameters were being tweaked to get those gains. Given that the tuner can only go by the data they get, I would play devil's advocate and wonder how the gains were had. It isn't to lay blame as you even stated things do happen. It is to see if you should be driving it at all until PC reflashes it.

I was assuming you basically meant that the tune was done based on the second set of sensors (behind the cats). If so, you would be reading lean conditions as the previous poster noted. You also mention heat, which will pull timing and power. So, I was curious where the power came from if the conditions appeared lean and timing was getting pulled.

In short, yes I think the first sensors are critical for any tune to be made proper, especially a car like yours with so many odd mods.

Good luck bro. Who did the install?

 

actually, i'm sure the tune was based off of the dyno's o2 sensor and not any of the car's o2 sensors so the tune is still probably pretty close. the car will probably have more idle/off throttle issues than anything.

 

Mikey....I see how the tuner would see the dyno sensor as its final indicator, but isn't the car still reacting to its own sensors? I get confused on just how much play the sensors have in our ECU other than just throwing a CEL. I assumed they were also used for the ECU to trim as it goes?

Back to the tune. Does this mean the car needs to go back on the dyno and be tuned with the "new" O2 sensor setup?

Good Luck ALAN!! Hey, learning and only loosing a little time or money along the way isn't always bad. Keep pushing it with thought . I love the car's progress.

 

I was reading this and thinking the same thing. I'd have to think there's some adjustment in the ECU based off the o2 readings but I always thought it was much less important in a speed density car (E55) vs. a mass air car.

None the less where it would come into play the most is with drivability stuff so it's probably best to have the tune done again.

 

Pardon for being a little OT and a noob question...

Carbon build-ups in the internals all the way to the exhaust are from the unburned fuel, right? So I see your logic above... rich AFR = more fuel = more unburned fuel = more carbon build-ups.

Here's where I don't get:
And from all dyno charts I see, AFR is usually very lean in low RPM (like 13-14).

Why would people say that you'd have more carbon build-ups if you drive a car like grandma (e.g. RPM not exceeding 3K)? Wouldn't it mean that your car would run leaner, hence, less carbon build-ups?

Alan, good luck... hope you could get this resolved before the next competition to hold on to the AMG flag...

 

Alan,

Was Jeremy using your onboard O2 (the one you told me you installed for datalogging/etc that is independent) or a tailpipe O2 from the dyno? What is your current catalytic converter setup? Do you have stock cats, one pair of cats, high-flo, etc? Where are your O2 sensors?

IMO, as long as the tune was done from the tailpipe it is ok, but the car itself isn't going to run well with O2s swapped. It will sputter, throw codes, and generally run rich as it's seeing lower O2 values than what are actual and will be adding fuel to try to meet them. This will explain fuel smell on startup, misfiring, etc.

Under WOT, this will be less of an issue, but in the long term running rich can foul plugs, lead to carbon build up, etc. I would get this addressed asap, and just get the sensors swapped. I don't think there will be a need for a retune, unless again, a tailpipe O2 was not used.

-m

 

I never ended up installing my wideband due to some missing hardware needed to complete the install. BTW...Innovative Motorsports has some of the worse customer service I have ever came across. I would highly recommend not using them based on my experience. As a matter of fact I'm switching to Zeitronix-Dashdaq just for that reason.

My current cat setup is a Magnaflow 200 cell race cat with O2's located pre and post. We used the tailpipe sniffer provided by Autowave.


Once the O2's were wired correctly 95% of the issues were resolved. The only thing I get now is a slight fluctuation at idle with the car in neutral. When in drive there are zero issues and things are normal. My tech recommended checking my AFR's at idle because he notice my car seems to be constantly trying to correct itself in terms of rich to lean. The idle itself isn't very bad but just on occasion the RPM's drop just a tad and it seems like the ECU revs up a little to keep it from stalling.

You are 100% spot on, under WOT the car pulls like a freight train. I've only done a few hard runs after the tune was done and I could definitely feel the gains both on torque and HP.

One thing I did notice this time around is that my car seemed much more sensitive to heat, which made tuning somewhat difficult. It seems like my ECU was constantly adding fuel even though IAT's and engine temps were good. THe last time I had my car tuned the temps were about 10-15 degrees cooler and we did between 18-25 runs within a 3 hour period. My numbers were always very consistent varying only slightly. This time around my numbers would change quite a bit during a back to back to run and this was very unusual for my car. I've already contacted PC and a re-tune will be done and hopefully afterwards my issues will be resolved 100%.

Thank you for your post Marcus!!!

 

Sorry to hear about that, you were pretty excited about their O2 setup. Good to know.

You may still have some adaptations all screwed up because of the length of time you ran the O2s swapped. You have some short term and long term O2 values that may need to be reset in order to get these little sputters resolved. I would try disconnecting the battery overnight and letting the ECU start fresh and see if that helps.

That is interesting and could be a complex issue relating back to having the swapped O2 sensors for a period of time. I would try and see if swapping them back and resetting the ECU eliminates this and only worry about it if it's still an issue. Might as well try and eliminate the swapped O2s as a variable and then if we still have to deal with this we'll have one less question mark.

-m

 

Yeah...I'm very disappointed in Innovative's customer service towards me. James from ACG gave them a call asking a few questions and the guy started yelling at him.... The only thing we were asking if they could provide us with the missing piece either at my expense or their expense, why get so excited. He kept on telling us it was supposed to be in the box....over and over again. Just plain rude IMO.

My tech already reset all the adaptations the night he fixed the issue.

When I first starting getting the rough idling and random misfire codes Serge did me a favor and rest all my adaptations. This didn't help at all. I'm thinking we should consider the fix a step forward and eliminating 95% of my problems. All though like you mention it might be a complex problem.

 

Have you checked your plugs? Checked your cats? I don't know how long you were running rich for, but it sometimes doesn't take long for it to do more harm that may require additional fixes. I'm thinking you need to check your plugs, check your cats (make sure they aren't clogged). Also (less likely) your valves could have had a little carbon build up on them, and this might cause them to get a bit sticky or otherwise cause some misfiring/etc.

Does anyone know off the top of their head what size are our stock injectors? I hope Alan wasn't running them at an excessive duty cycle with his power levels and O2 readings?

-m

 

don't know what size they are but there's still room before they max out their duty cycle.

 

I just had my plug and wires changed while my car was at the dealership getting fixed. My old plugs were all evenly worn with the usual wear and the tech also noted no indication of running rich or lean. He also noted that no metal flakes of any kind were noticed on the electrodes .

Since my wiring was fixed I haven't received any of the misfiring codes.

Marcus, when you say excessive do you mean possibly running out of fuel during a WOT run? Do you also mean with the combination of the swapped O2's and the levels of fuel I'm running now that there could be a problem or damage? I only had a few wide open throttle runs not including the dyno but all seemed well.

 

Has Powerchips attempted to re-load your prior tune, in order to eliminate software as the cause of your irregular idle and AFR corrections.

 

No, but the irregular idle was before the initial tune. I believe, but not sure that a re-tune would correct my slight issue I'm now having with my car. I have no doubt if it's a tuning issue PC will handle it. I'm actually going to take my car to one more tech just to make sure something wasn't missed. I definitely want all the possible kinks worked out before having my car tuned again. No one ever said modding was easy .

 

Tell me about it.

I hope you get it all sorted. I'm eager to read another one of your record breaking threads.

 

I'm confused on how the tune could be "true" if the car had swapped sensors at the time? Wouldn't the car react completely diferently based on what it reads?
I always saw ECU tuning as a combination of inputs and outputs. How could a parameter be dialed in if the output from the car isn't there? I can see how the tune may have been optimized for "max" or something but not throughout. If anyone has insight, it would help.
Too bad you don't have the datalogger hooked up or you could send PC some data and have them tweak your tune some. When are you coming down again? I would definitely plan another dyno tune once you have everything checked. Not as much for safety as for leaving power on the table, especially accross the band.

 

No doubt! I promise I'll be having that thing back on the dyno once everything is checked and the car is 100%.

 

Jangy,

The tune was done taking readings from an independent tailpipe O2 sensor connected to the dyno, not the onboard OEM sensors. That's why it wouldn't affect the tune.

When you get an AFR chart from the dyno, it's taken from a sensor stuck in the tailpipe, not from your onboard sensors that the ECU uses.

-m

 

Alan,

I'm just trying to go through the "usual suspects" when it comes to the issue you are describing, and unfortunately they are quickly being tossed out the window, which will ultimately lead to more time consuming and difficult to perform remedies.

Fuel injectors don't like to be run at 90 or 100% duty cycle for a very long period of time. They typically like 80% or less (I'm speaking in general terms here) for accuracy and reliability. Usually if a car runs out of injector, you'll see it start to go lean, but in your case, the car could be calling for a lot of fuel when you didn't need it, so my thought was that it would max out the injector duty cycle for extended periods of time and could have lead to them having an issue or something. Mikey has said that our injector sizes leave plenty on the table so that is probably a far fetched idea.

At this point there could be multiple culprits... a sticky valve, bad coil pack, on and on. The good thing is the car is still making power, the bad thing is the misfire could get worse, depending on what is causing it.

-m

 

I understand that part. I just don't get how the OEM O2 sensors don't come into play as the car is being tuned. Basically, as the car is even baselined, it should have been running mighty rich if the O2s were reversed. Had the car been straight, the car would be running only as rich as his new mods would make it but likely less rich than with reading a post cat O2 sensor. Hope that makes sense. Then, you begin to tune based on the tailreads. If already so rich, what do / can you do? Had the car been more normal at the start, would there not be a more proper potential tune?

I dunno if I am getting my question accross but this is a very interesting topic and I am big time into learning about our ECUs so i just wanna understand. sorry for the repeated questions.

 

Great discussion here, unfortunate indeed.

Alan, you got the re-tune after adding the LT's?
I hate the fact you had dialed her in so nicely and now have a problem.
Please let me know when you come down.

Thanks for the detailed input Marcus.