Lean gst

[Gst to the max]

Alright guys, so I really need some help with my 95 gst. According to my wideband I'm running lean at boost and i have not the slightest clue why. I'm still a rookie at this so excuse me if I ask dumb questions. At idel my car sits at a grand and afr is 14.1 at 3500 and 10 pounds of boost afr is 11 to 12 so I'd appriceate any help.

 

[BLOHS7844]

11-12 isn't lean during boost. Especially at only 10lbs

 

[Gst to the max]

Then what about when I lay the fuel to it at 10.8 at 15 pounds ??

 

[GSTurbo1]

10-11 AFR is perfect for boost... 14 is idle anything >14 IS A NONO

 

[Gst to the max]

Alright, thanks guys I just got into this stuff and I am trying my best to build my car right, so far it has a tdo5 16g big will tubed header new intake(not the manifold) dc sports exhaust. All the odds and ends have been taken care off that why I was like what's up with my afr, I just saw my wideband reading lean and didn't like it so figured I'd ask what's up. Thanks for the advice.

 

[H@xtGSX]

It sounds like it is doing exactly what it should be doing. Remember, the lower the number on the wideband, the richer the fuel mix is.

 

[Gst to the max]

Alright thanks guys, I just wanted to make sure nothing was seriously wrong I'm ordering dsm link v3 soon I'll put updates of the car on here after

 

[Gst to the max]

Ok guys so this is a little off topic but my car leaks oil now of cours it's a 4g63 6 bolt but how do I know if I have the air cooled oil filter housing or not. Because that's where the oil is coming from. I just to know which one to buy.

 

[NHerron]

Probably the water cooled one, as it's easier to come by than the air cooled.

Pictures attached

First one is water cooled (note rubber lines along the block going in and out of the 'sandwhich' plate)

Other one is air cooled. Note the large unplugged outlets- these go to an external air cooler (looks like a small radiator, mounted somewhere behind the bumper) via two decent size hoses

 

[Gst to the max]

Thanks man, i just wanted to make sure I was buying the corrected one there to expensive to order the wrong one.

 

[NHerron]

No problem

The threads in the water cooled one is 3/8 BSP, not NPT, but pretty darn close. Not sure on the air cooled one, I think it's a straight thread type utilizing copper crush washers for a seal.

Good luck

 

[Gst to the max]

Problem solved, it was leaking from the oil sending unit for the factory gauge I went ahead and pulled the hole housing of just to check for cracks or what not. There were none, I put a rubber washer around the threads of the sending unit and some gasket maker. It sealed it all up.

 

[NHerron]

Good to hear

 

[Gst to the max]

I found most of my problem with my air fuel ratio and it is the fact that my o2 sensor before cat isnt reading there for the Ecu is telling the car that it's not getting enough feul and it dumping the feul like crazy. My gas mileage is horriblle. Does anyone els agree with this ?

 

[WES_393]

I found most of my problem with my air fuel ratio and it is the fact that my o2 sensor before cat isnt reading there for the Ecu is telling the car that it's not getting enough feul and it dumping the feul like crazy. My gas mileage is horriblle. Does anyone els agree with this ?

Yes, a malfunctioning front O2 will cause issues with A/F ratio. Contrary to previous advice, you shouldnt even be above 11:1 AFR with the stock tune. Idle should hover around 14.7:1 when warm at idle/cruise. Anything higher or lower is a sign of a problem.

 

[Gst to the max]

Alright thanks man, I'm replacing the o2 today maybe even relocating it and putting my wideband o2 in my o2 housing and the car o2 in the down pipe.

 

[NHerron]

I think Wes has his WB in place of the front 02 sensor. Can't remember for sure

But with DSMlink, you can use your wideband sensor to simulate the stock narrowband front 02 sensor, as well as using it as a wideband. If you have link, and use the wideband in the stock front location, just simulate the factory sensor. It wouldn't be the best idea moving the stock 02 sensor back there to the DP.

 

[Gst to the max]

My wide band sensor is in the o2 housing for the factory sensor. I don't have link yet cash is just short and link is 530 dollars or somethin close to that. But this December is when I'll be doin my tuning and I'll mess with the sensor then. For now the factory sensor is in the down pipe and at idel it's running 14.1 and then 11's on boost.



Alright guys I have a question idk of its a stupid question or not but anyway, can boost leaks affect Afr? I'm sure I have a few minor boost leaks that need to be fixed but my afr is a little high right now(just drove it a few minutes ago).