Denso universal air fuel ratio (upstream) sensor and universal high flow cat converter search (1 Viewer)

[alia176]

Hey fellas,

According to the 'net, my '96 needs a Denso 234-4157 which is the upstream air fuel ratio sensor. I'm redoing my exhaust since I now have a turbo installation and thinking about ordering an universal high flow cat with a sensor port (on the inlet side). Will this Denso 234-4201 work?

If you know of a true high flow cat converter with two sensor ports, let me know please. If such an animal doesn't exist, I'll get a cat meant for a 8.1 chevy, something like this

I happen to have two of these 234-4260 on the shelf, from another project and was thinking of installing one of them post cat converter.

As an example of a cat converter with a single sensor port, here's a Walker

 

[alia176]

Been going down the Catalytic converter rabbit hole over the weekend and found out some answers. A call to Magnaflow confirmed what I learned from this video. Definition of "high flow" is 200 cell per sq in (CPSI). Typical OEM application includes cats that are 400 or 600 CPSI, in another words NOT high flow.

Lady from Magnaflow suggested I use this product and she didn't understand FI and all that gobbly gook, p/n 59956. This is a high flow with 2.5" in/out.

Just a FYI.

 

[CJK]

Disclaimer: This is based on research but I’m not an expert


I believe O2 sensors are universal, all the different part numbers are just for fitment into your specific exhaust system.

If you’re redoing the exhaust, I can’t imagine a reason why those 2 sensors you have would not work. Weld-in bungs are super cheap and simple…seems like the easy way to go.

Side note: if you have Spartan II wideband o2 sensor attached at downpipe, It has a narrowband output which can be connected to ECUs (as it’s the same output range as the Pre-Cat OEM sensor). I imagine you could just use this and then you only need to weld in one bung post-Cat.

 

[alia176]

Disclaimer: This is based on research but I’m not an expert


I believe O2 sensors are universal, all the different part numbers are just for fitment into your specific exhaust system.

If you’re redoing the exhaust, I can’t imagine a reason why those 2 sensors you have would not work. Weld-in bungs are super cheap and simple…seems like the easy way to go.

Side note: if you have Spartan II wideband o2 sensor attached at downpipe, It has a narrowband output which can be connected to ECUs (as it’s the same output range as the Pre-Cat OEM sensor). I imagine you could just use this and then you only need to weld in one b

The upstream O2 sensor in our case is used to control the duty cycle of the injectors by the ECU, therefore, it's called air/fuel ratio sensor, not an oxygen sensor. The downstream is a simple O2 sensor . When you order Denso units from Amazon, you'll see specific Upstream and Downstream designations.

Good info on the Spartan II wideband sensor, might look into that. I'm curious as to how the Spartan unit sends out four wires typically needed for our OEM O2 sensor connector. Since Joey provided the sensor bung right after the turbo, it'd be nice to have one sensor that does two things. Thanks again for the idea.