I have 2 questions that need urgent help. I have the comp cam 224/230 and headers and i had the mufflex 3" y-pipe with a 4" collector. Well i couldnt get the thing to fit so i had an exhaust shop build me one. My question is going from a mandrel bent one to a custom built one, Can i lose horsepower. Its alot quiter and doesnt feel as fast now. It used to be real loud in the higher RPM's and now its pretty quiet. Some of the bends in the new y-pipe are pretty small since its not mandrel bent. Some opinions on this please. Also what is a code 134. I know its an O2 sensor but does that mean its bad or bad wiring? Thanks

 

Does Anyone have any suggestions?

 

P0134 = Heated Oxygen Sensor (HO2S) insufficient signal activity Bank 1 Sensor 1

Either the sensor is bad or the wiring is bad. Swap the pre-cat sensors side-to-side. If the problem follows the sensor (P0154), it is a sensor problem. If the problem stays on the drivers side, it is a wiring problem.

Unless you've got some mods that are not in your signature, its not likely that the differences between a mandrel bent 3" Y-pipe and a hand fabbed one are going to show up as any difference in power. (Just curious.... why didn't you just have them alter the 3" Mufflex pipe, rather than cobble up some apparently poor quality bends?) Might change the sound, which makes you think its not as fast. But SOTP isn't usually very accurate.... do you have before and after track times?