Car staggers in 3rd gear

[Kevin T.]

I have a 2000 Camaro 3.8l with the T5 tranny. Whenever I am running my car hard when I hit third the car makes a popping sound coming from under the car around the front and the car jerks and staggers. It only does this in third gear and does it slightly and more than rarely when im just cruising around not going above 3000RPM. It is most noticeable when I am racing or just accelerating fast. I think it may be either a loose bolt in driveshaft where it meets the tranny or either my clutch is going out. My PCM is slightly malfunctioning due to me using the motor cleaner at the car wash and it getting all in the PCM. I think it has nothing to do with the PCM since I hear the popping sound. Any help would be great.

Thanks

[Smells Like Rubber]

Is a popping like a miss fire or like metal clanking?

[Kevin T.]

metal clanking, nothing like a missfire. I must add it does it in all gears if I rev each gear to past 4000RPM. For example when I was pulling out of work today I saw a mustang drive by so I pulled out and matted it revving 1st and 2nd to 4500RPM and I revved third gear to about 3600 RPM and shifted to 4th,the car started staggering like usual but now it was in 3rd and 4th. The shifter was moving rapidly, if i was'nt holding it tight it prolly would have fell out of gear.