This may be a stuipid questions but do I have to add anything to the car if I want to get my A/F ratio plotted during a dyno run?

I just spoke to a dyno shop and he said he would have to add a bung to the exhaust for $40 in order to do a wideband A/F plot. Is this true?

Thanks

 

that is absolutely not true... find another dyno.. thats old technology... find a new guy... they can plug right into the 02 sensors etc...

 

My dyno guy put a wideband probe up each tailpipe. I was not aware you could unplug the sensors and use them for a tune. I was aware of welding the bungs in and did not want to answer ouestions from dealer service manager as to why they were there. Learn something new every day.

 

There not a must to Dyno your car but below is just food for thought.

From Alternative Auto.

"We also employ a state-of-the-art wide-band Air/Fuel sensor. It is extremely accurate and is installed in the exhaust as near to the manifold or headers as possible.
Our wide-band Air/Fuel sensor has to be installed in an available, dedicated 02 bung in front of the catalytic converters. This extra 02 bung is welded in at our facility or by a local exhaust shop when we are performing tuning services to a vehicle. Sensors that are simply inserted in the tail pipe can be extremely inaccurate because a vehicle's catalytic converter alters the A/F ratio."

http://www.alternativeauto.com/tuning/tuning_main.html