I am completely inexperienced when it comes to hands on mechanics, though I do understand in a theoretical way how things generally work.
I have an Acura Integra 1997 LS that has been gradually augmented over the years. Parts installed by mechanics. Parts selected by me.
For some reason just recently, the tone of the exhaust has changed, and I feel I can smell exhaust fumes when I approach wide open throttle and/or high load. The change in exhaust sound is hard to describe, but like when a trumpet or sax player decides to use more 'breath' and kind of flutter with the tongue before the mouthpiece. Like if you try to roll an 'R' quickly while blowing through a narrow opening.
I tried crawling around next to the car all along it, while the Mrs tried covering the exhaust end with a cloth, while pumping the accelerator, and even under load (handbrake). I can smell the exhaust under the car perhaps more strongly than behind it, though there is no visible sign of where any leak might be, and I cannot identify a position. It seems as though the sound is coming out of the end of the exhaust, but I can't find where the source of the problem might be.
Could someone please help with finding where the problem might be. Might it be wise to just jack it up and tighten whatever I can find. Oh...I should also add, there is a new resonance somewhere too - at over 3000rpm something buzzes much more than it did before (there always was a brief buzz at 3000rpm). The exhaust is a stainless Tanabe catback. Cat a hi-flow of some kind I can't remember the brand.