So the situation:

My personal car experienced a wideband issue. It ended up being a dead brain unit but I believe the sensor should be fine. I replaced the brain.

I used to log my drive every day from December til about March.
I had my AFR's at a solid 11.2 under boost after 3500 RPM til redline.

Recently I haven't been logging but noticed my display has shown me as extremely rich. Down into the 10's and sometimes 9's.

I figured this may be due to temperature changes.

I started logging again and tuning to bring the tune back to my 11.2

Now I am getting a sudden knock at around 4500 consistently and am not sure what to make of it. Screenshot included.

Opinions?

I think there may be 2 issues:
1. Wideband not working correctly. Maybe it's telling me 10.5 and it's actually 11.5 or something like that. I don't know how to tell if a sensor is bad and when it goes bad, how it manifests itself.

2. Temp compensation messed with me and needs to be adjusted to slide everything back.\


I'm just worried that I may be adjusting AF based on a false sensor.

 

If the wideband heater wasn't keeping the sensor hot the sensor is probably bad. Also if your in the 9's that is approaching dangerously rich to the point of washing out cylinder walls. Ask me how I know. Also early 03 evo's were reflashed by mitsu because of a super rich condition which they feard would lead to damage that would have to be covered under the warrany (mid 9's AFR).

 

i wish i knew what to tell you... that is a lot more timing then i run at those parts, but my load is a lot higher as well. Maybe you can get your hands on a new sensor and swap it out.... what kind of wideband is it ? you know you can go to the VW dealership and they have O2 sensors there for pretty cheap

 

It's weird my old map worked really well. No knock.
Made 306awhp and 312tq with that map.

I adjusted my MAF scale so that may have something to do with it.


I haven't changed my timing map in a quite a while. I've retarded a tiny bit but it hasn't seemed to change anything.

I use an innovate LC-1. VW sensors work with that?


Maybe I have a bad sensor. I'll take one out of someone elses car and test it out. What a pain in the ***.

 

I'm pretty sure 02+ 1.8t VWs have a 5v O2 sensor before the cat. Not 100% on the year though. You could probably check www.vwvortex.com for info on that.

 

VW part no 021 906 262 B, Standard SG897 or Bosch 0 258 007 057 are all part numbers for the Bosch LSU4 02 sensors.
www.busdepot.com

 

Your sensor is not the problem. If your sensor was dying then the LC1 will give you an error code.

Your just running too much timing. Your timing looks stock to me @ the point of knock. Pull 2* of timing @ 4-4.5 K and that will eliminate you knock.

 

Post your fuel map? Stock turbo stock injector maps will be pretty uniform assuming we know if the lean spool is on or off and if you have a pump or not.

 

i think your timing is a little high personally, but i have seen you post enough in here to think you know what you are doing.... but i will say this, if JB cant help you, noone can lol.

Post your map and let everyone see what we can pick apart

 

Why did you change the MAF scale?

That does affect the overall AFRMAP ..

Also .. you're using calculated load or 2byte load?? you could be changing the wrong region that's why it doesn't seem to help .. since you changed the scaling, the calculated load and ECU load may no longer be the same

 

I think it's my sensor. I did a full calibration last night and the sensor read from 7.35 AFR to 80 AFR. Something seems definately wrong.

That and when I datalogged, my previous values in the 10's are now in the 8's.

Picking up a new sensor today hopefully.

Thank you all for your help.

I agree my timing may be a little much, but after repeated dyno'ing and datalogging I really haven't found any sort of knock.

I do have lean spool disabled and I am logging using 2 byte.
I scaled my MAF because of my intake.

 

FYI.
The VW dealership wants 88 bucks for the sensor.
Advance Autoparts wants 67 bucks.
They will price match to www.busdepot.com at 49 bucks.

http://www.busdepot.com/details.jsp?...ber=021906262B

Arrives next day.

 

good info.... i have always been getting them from VW as a suggestion from Cobb tuning because thats what they do i guess

 

I just ordered one from the bus depot even though I have two of them. This is the cheapest that I have seen them.

 

New sensor installed.
Will be logging tonight but at first glance it looks much better now.