I've been running into a lot of cases where I'll either need to run a log on a vehicle or work on the tune, but the vehicle doesn't have a wideband at all. Some don't know they need one to tune with, some just don't want it entirely. I've googled around a bit...does anyone know of a clip-in type wideband? Something similar to what dyno shops use to get AFR readings. I'd like to just be able to put the wideband into the exhaust pipe and pull information from there. As long as its quick and easy to install and remove, it should do the job.

 

Something like this?

http://www.innovatemotorsports.com/x...cat=271&page=1

 

The problem there is, you need to measure the AFR before the catalytic converter, not after.

 

how do dyno shops do it since their system is also post cat?

 

I would look into running a WB as NB too and put it in the stock O2 location. On the EFIlive forums they say it is possible to do this, but I haven't sat down to figure it out yet. That way you could just remove the stock O2, and install the WB. Plug in the WB to the NB plug, and run the serial to the FlashScan. When you are done, just pop it out, no welding, no extra bung.

I have looked into the post cat WB thing, and have never gotten a good answer. Tuning shops say it is fine, and people that tune their own vehicles say it isn't. I would believe if you are tuning your own vehicle that you would spend a bit more time to the detail of a tune.

 

Keep in mind that its not a quick endeavor crawling underneath an f-body to swap a WB for a NB. Nor is it easy to mess with any O2 sensor that has been rusted in place lol.
I suppose I could aim rich on cars that still have cats because they're not likely to be hardcore power seekers still having the cats on their vehicle.
It makes sense that a post-cat WB would give you a poor reading because of the chemical conversion that takes place...

 

I have both the LC-1 and the LM-1, Using the tailpipe clamp, on a boosted vehicle. The LC-1 was installed pre drivers side cat, the LM-1 at the tail pipe with the exhaust clamp. The AFR reading was less than .1afr off between the two WB's. The placement of a WB sensor only matters when the cats have an air pump to supply additional air, Like the cars from the 80's, or if you have exhaust leaks that pull in fresh air into the exhaust stream. If your set up does not have either of those conditions, then it is fine to place a WB sensor anywhere on the exhaust stream.

 

Less than .1 off, that's good to know. Certainly makes using the tailpipe clamped sensor more appealing. Thanks for the post!

 

I suppose I'll snag that tailpipe clamp and an LC-1, then.

 

I was talking to someone who's way smarter than me today (it happens all the time!! ) And I asked him about this since he's been tuning cars since the Model A came out and he also said the same thing as Reynaldo mentioned above. He's done both at the same time and found at worst about .3 in difference. He explained that there are four parts to the chemical make-up the spent exhaust gasses and the cats only effect 2 of them but don't effect other 2 that is actually what the sensors read. My brain glazed over pretty quick in the convo but what I walked away with was that it really didn't make as much of a difference as people initially fear.