sounds like mufflers is right under my hood... sounds like its a hole in the catback...

question

I planning on a rb20 or rb25... if I do the catback and new muffler now, will everything line up?

or should I spot well the hole?

 

If its under the hood man....you might wanna check your headers, lol. Could be rusted out, or any part really before you 02 sensor. If its before your 02 sensor then you getting bad readings. The 02 sensor reads the amout of oxygen in your exhuast flow and sends it back to the ecu letting it know how much fuel and air to mix. So it effects performance. Most likely if its rusted you dont wanna spot weld it, find out were it is first.

Robbie