So recently bought an 02 Z on here from a forum member... The car was relatively tuned with the following..

NLP Custom Cam 232-236 113LSA
Crane Pushrods .080 Chromoly 7.450
CNC 243 Stage II Cylinder heads, dual valve springs, Titanium retainers
Hypertech 160 Degree Powerstat
SLP Underdrive pulley C5 SFI approved 25%
GM Performance plug wires
Custom Dyno Tune
ECS Trans-Diff Brace

430 RWHP

Vehicle also had Kooks LT Header, off-road cross pipe and a "muffler shop" exhaust which actually put out an awesome note when I purchased the car 3 weeks ago. (Didn't notice the exhaust brand at time of purchase.)

Vehicle was purchased in Jacksonville, Fl, and driven back to Chattanooga, TN.

For a couple days the exhaust note was incredible, and the CAM hammered.

I took it to a local tuner (In Tune, in Cleveland, TN) who leaned out the car about a point and a half, tuned the vehicle a bit more to his recommendations, and ran a new dyno. Tuner was incredibly impressed with the original tuning of the car, but had some changes and recommendations.

No issues here, then literally overnight (couple mornings later) I start up the car, the CAM barely rocks, the mammoth exhaust note sounds completely stock nearly, etc.. (Vehicle didn't seem to be affected power wise upon first noticing this.)

Well by now I am completely stumped, call the Scott the tuner who assures me the tune would have nothing to do with this...

Upon further inspection of the exhaust I notice it is literally a "maxi muffler" type setup. 4" to 2" to 4" pipes, no mandrel bends, oblong tubing, etc..

I quickly put a post here seeking a B&B Bullet and find one.... Get it in, installed and was put in awe at the sound of the renewed exhaust...

Well all is fine for a few days, until yesterday. Get in the car, start it up, and the thing no longer roars, but in fact purrs.. Granted, if I step on the pedal, it comes alive, but nothing like initially upon install. As of this evening, the car feels/sounds mild, with the CAM being barely noticeable also.

My question: Air/Fuel mixture a possible cause? (Friend made a recommendation of this.. Constant weather changes.. 70 one day, 35 the next.)

Compression issue a possibility? (Another recommendation from a friend.)

The reason I mentioned the pick up location to my current location was the very difference in temperature, etc.. 65 in Jacksonville when I pick up the car, 30 in Chattanooga by the time I get it home.

B&B installed on a very cool day, after a few days we start to see very warm, very dry weather.. Is this a possibility?

Any other recommendation or considerations would be greatly appreciated.. My tuner is baffled, my fellow car club enthusiasts are baffled, my local muffler shops are baffled..

(My first run into American muscle, so of course I am oblivious...)

Thanks again..

 

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