O2 sensors on cats

Yes, you must have the O2 sensors. They're not "optional" equipment. Whether you plug them into the test pipes or leaving them dangling in the air, that's your choice. Leave them dangling in the air, and I'm pretty sure you'll experience other problems in short order.

Do it right, have a bung welded into your test pipe or buy proper units with the flanges and stuff. Ricambi sells them.

 

Hi

On workshop manual you can see that when removing the 02 sensors the engine works in open loop operation; that means that the engine works with predefined ratio air/fuel and there is not correction by the ECU.

This operation mode (open loop) is normally activated by the ecu in 4 cases:
1) cold oxigen sensor (less that 300° C)
2) cold water (less than 50°C)
3) oxigen sensor in short circuit or open
4) full throttle (throttle position >72°)

I don't know about the engine ligth, because I have an EU version of 348, that do not have this light.

Bye
Renato

 

Daniel's advice is good. The quality pipes have fittings for both the O2 sensor (which must be fitted for economy/performance) and the temperature thermocouple (just for completeness, as the pipe gets nowhere near as hot as a cat). This is what is fitted to my car.

Take care removing the O2 sensors from your old cats, they are easily damaged. It would also be a good idea to order new donut gaskets at the same time as the pipes.

 

One last consideration... you might be exempt from emissions in Ohio, but having test pipes on your car will be a serious hinderance when it comes time to sell. Either keep your old cats for reinstallation, or ditch the idea of pipes and just install HyperFlow cats.

 

i live in florida and have test pipes with 02 sensors in them. No problems. I did save my original cats.

 

ditch the idea of pipes and just install HyperFlow cats.[/QUOTE]

The best advise. No down sides to this suggestion. The sound, performance and legality are all still there with no CEL's. I think we have seen the end of a trend with the test pipes now that there is a quality alternative available. Folks have no idea how much effort and time Troy puts into designing his replacement cats. Every small aspect regarding changes and how to make it better have been covered and addressed. I have spoken with Troy at length about his designs, some ideas that would save him costs in manufacturer, and only performance / quality / fitment issues are looked at by him. A TRUE breath of fresh air in this market place and one that will be here for the long run!

Dave

 

My righthand 02 sensor went bad and shut down the engine. I unplugged the Cat ECU's and problem solved....or so I thought until I read this thread.

I 've been driving around with a defective 02 sensor and no ECU's.

I assume therefore that my car is'nt running correctly???

In addition, I've been told by a reliable source that the Cat ECU's should'nt be removed on a 2.7 verion of the 348.