New tune, new front 02 sensors, now I have the CEL coming on

[beastmar]

So I recently had my car dyno tuned and my tuner had recommended that I replace the front 02 sensors because of the some of the wires were soldered together from being cut. So I sent him the datalog file with the new sensors just in case it changed anything and he had sent me another custom tune. I installed the new tune into my car and I am running into some issues.

My car has (2) new NGK front 02 sensors. After some driving, my check engine light illuminates and I get these codes P0053, P0172, P0175. I googled them and my banks are running rich. What is the issue? Could it be the new 02 sensors?

FYI: I am running E-85 and the sensors description specifically mentioned safe with E-85.

 

[BLOWN9646]

Did you check the fuse?

Edit: ho2s-12

2nd Edit: could be "Box in car..f2-8. 20 amp"

Maybe hotcobra03 will confirm

 

[gt347mustang]

Post the datalogs

 

[beastmar]

Did you check the fuse?

Edit: ho2s-12

2nd Edit: could be "Box in car..f2-8. 20 amp"

Maybe hotcobra03 will confirm

I will check my fuses. I can reset the code and then maybe after 50 miles or so, it'll come back on.

Post the datalogs

Which PIDs would you like to see?

 

[gt347mustang]

Stft ltft all 4 o2 sensors, rpm, load, throttle pos ect

 

[gt347mustang]

Post the datalog you already took.

 

[beastmar]

Post the datalog you already took.

Please see below. I did not datalog the 02 sensors

 

[gt347mustang]

What does your tuner have to say? B1S1 looks to be functioning properly in the 02 log.

 

[whitedevil95]

Dantes MP?

 

[c6zhombre]

What is the source of the E85? If it's from a pump, did you test it? How many tanks of E85 have you run and was the tank completely empty of pump gas before the tuning began?

You really need to know what the ethanol % was during the tune session so you know what to expect if ethanol % changes happen at the pump for future fillups. Let's say you were tuned for spot on 85%....then ran that tank down with no issues and go to fill up again. If that new tank is not tested, and lets say it was 60% ethanol.....the car could very well start tossing out those rich codes

 

[beastmar]

Dantes MP?

Yeah DMP

What is the source of the E85? If it's from a pump, did you test it? How many tanks of E85 have you run and was the tank completely empty of pump gas before the tuning began?

You really need to know what the ethanol % was during the tune session so you know what to expect if ethanol % changes happen at the pump for future fillups. Let's say you were tuned for spot on 85%....then ran that tank down with no issues and go to fill up again. If that new tank is not tested, and lets say it was 60% ethanol.....the car could very well start tossing out those rich codes

It is from a pump. I have tested the E85 and according to my test, the minicus is right at 83-84%. I ran about 2 tanks before the tuning began and yes completely drained all E85 out. But I did fill up at a pump that I never tested up in Los Angeles and the check engine light popped up more than usual.

If the ethanol content was less than what is tested, why would it through a rich code? I would imagine that it'll throw a lean code right?

 

[c6zhombre]

Yeah DMP



It is from a pump. I have tested the E85 and according to my test, the minicus is right at 83-84%. I ran about 2 tanks before the tuning began and yes completely drained all E85 out. But I did fill up at a pump that I never tested up in Los Angeles and the check engine light popped up more than usual.

If the ethanol content was less than what is tested, why would it through a rich code? I would imagine that it'll throw a lean code right?

It will throw a rich code because an 85% tune of ethanol is requiring 30-40% more fuel to maintain a similar lambda a/f ratio at WOT as a gas tune (E10 gas tune stoich is like 14.1/1 and E85 is 9.75/1 or somehwere in that vicinity). So, if you have it tuned for 85% ethanol, it's really throwing a ton of fuel at it because it's expecting a certain ethanol %. Your E10 pump gas tune is requiring a lot less fuel than your E85 tune.

This is why it's smart to test every single time. Just in case. It's also not a bad idea to get your tuner to maybe make you an E55-E60 tune just in case you get some super shady winter blend stuff. By law, unfortunately, I believe ethanol can be as low as 53% these days and they still market it as "E85".

 

[c6zhombre]

Here's a quick n dirty summary:

-Have perfect E85 tune.....fill up with anything testing less than 85% ethanol = rich
-Have perfect E85 tune.....fill up with anything testing more than 85% = lean

None of these scenarios "normally" are a big deal or pop cel lights unless they're way out of bounds, like 20% or more difference than what you're tuned for. If you see E75 to E90, I wouldn't worry and highly doubt any cel will pop, unless there's some other issue going on besides fuel ethanol %.

 

[beastmar]

Here's a quick n dirty summary:

-Have perfect E85 tune.....fill up with anything testing less than 85% ethanol = rich
-Have perfect E85 tune.....fill up with anything testing more than 85% = lean

None of these scenarios "normally" are a big deal or pop cel lights unless they're way out of bounds, like 20% or more difference than what you're tuned for. If you see E75 to E90, I wouldn't worry and highly doubt any cel will pop, unless there's some other issue going on besides fuel ethanol %.

Got it. Thanks for the help man. Hopefully I can track this down to the fuel. Once I fill up with my normal E85 station, I'll report back if I see a CEL turn on.