Mechanical Malady or Tuning?

[Shane's93LX]

New to tuning and no time with my job to really get to know the language, but hoping someone has encountered similar symptoms and found a solution:

Tune is custom and done remotely from a reputable tuner, but he's pretty busy and I think his job is done until I get the other pulley/belt. Setup is '03 with full exhaust, VMP with VMP3000 MAF on the stock unit.

Cold start or hot start, the first few minutes of driving registers a rich A/F, like 10.2 - 11.2:1 at idle. Under ANY load where compression starts, the car stumbles, maybe like there's way too much fuel. And if you watch the A/F, as soon as it registers a normal idle A/F like 13.X:1, loaded acceleration is totally normal and without issues.

Also, a quick blip of throttle makes the car stumble at any operating temperature, but I hear that's attributable to the GT500 TB (mech link).

The check engine light has thrown the following codes several times:

P1115: intake air temperature 2 (iat2) ckt high output (super/turbo charged)
P0148: fuel delivery error
P2195: 02 sensor signal biased/stuck lean (b1, s1)

Maybe just buying new 02 sensors is worth a shot for starters?

 

[decipha]

do u have an x pipe?

bad iat2 and fuel delivery codes are pretty major problems

 

[Shane's93LX]

It does: Kooks LTs and an x pipe. Maybe the 02 sensor code is a valid issue with one of them - it's likely they're originals.

 

[01yellercobra]

Sounds like it's a combination of the tune and the parts to me. You might try changing the IAT2 first and see where that gets you. For the O2 code I would swap the sensors side to side and see if the code follows the sensor. As for the stumbles, if the fuel delivery isn't right and the tune isn't dialed in you can have all kinds of issues.

 

[Shane's93LX]

Thanks for that, I'll give that a try at the end of the next work trip!

 

[blownfox]

Did you just install all these mods? Have you reached out to Joe? He's pretty knowledgeable about these cars. @cj428mach does his own tuning on these cars and just north from you. I had no issues with my GT500 TB except for the throttle looking loose. I will say my VMP 3000 has cause several issues during my remote tuning sessions. Extremely rich then really lean. It was not calibrated as advertised. I would log the car and send teh log to our tuner. He might be able to ID something.

I have 2 new 02's you could try out if you want.

 

[decipha]

I asked about the x pipe cuz its common to have o2 sensor codes with x pipes due to cross scavenging

this doesnt sound like your entire problem but no doubt its most likely contributing to it

as i mentioned earlier the fuel delivery and iat2 codes are major problems. Those have to be resolved before u can do any real troubleshooting.

more details here
EFIDynoTuning • View topic - X pipe Tune Adjustments Required

 

[cj428mach]

I agree you need to sort out the fuel and iat2 code. If after that you need a hand let me know.

 

[Shane's93LX]

Thanks all. I never even realized IAT2 had any effect on how it drives but that's my own ignorance talking. Connor, I'll hit you up about the 02s!

 

[cj428mach]

Thanks all. I never even realized IAT2 had any effect on how it drives but that's my own ignorance talking. Connor, I'll hit you up about the 02s!

Thats Garrett with the O2s, lol.

There are 3 of us with OW terminators in the area that I know of.

 

[Shane's93LX]

Ha, sorry about that!

 

[blownfox]

Ha, sorry about that!

What side of town you on? I'm south Greenwich and if you still need them I can PM you my number.

 

[Shane's93LX]

I live northwest, but I may not need them at the moment. Finally got a couple logs and it looks like the 02s are reading the same values. What I'm seeing to this point is open loop for the first few minutes of each start and during that time, any blip of throttle puts a a/f reading that's beyond what the wideband can read, which probably explains why it stumbles under a load. When closed loop comes back, it responds "normally" in the a/f range.

 

[01yellercobra]

Did you add to the Transport Delay and Heating Duty Cycle for the O2's since you have headers? I want to say I added about 15% to both of those with my old set up.

 

[Shane's93LX]

I'm working with a tuner and now that I'm reestablished, he saw the passenger upstream o2 was "lazy" and a new sensor cleared that up. As the schedules align I'll see if it clears up the rest of it.