2002 GTP
72k miles
93 octane
list of mods in vbgarage
I made a post awhile back about noises from the s/c and some other problems but the s/c is just fine but im still having issues. Im getting around 500-1000 rpm drops when coasting in drive or idling in park. It never drops when accelerating or when its in neutral (idling or coasting). When the rpms drop it will shoot back up to normal and drop down again right away almost in a "beat" until i shift into neutral or shift down a gear.
Here's things I have done so far
changed oil
new fuel filter
o2 sim (since I had the high flow cat)
fuel pressure checked (50psi key turned over, 45 idle)
now I am not too sure about what the fuel pressure should be at, I think if I remember correctly idle should be around 45 but i have no idea about or if it even matters with the key turned over.
Also, with the o2 sim installed it got rid of 2 codes. The p0420 and i can't remeber what the number was but the computer was reading lean from the o2 sensor. I can always just plug that back in and fine the codes it was throwing.
Everyone seems to think its a fueling and telling me to get an adjustable fuel pressure regulator but I read an article on ZZP how it can mess with your tuning and offer nothing more then the stock one. How likely is a fuel pressure regulator to go bad though?
*EDIT*
also since im running a 3.4 pulley shouldn't I be running around 11-12 psi? It goes at the very max 10 and at idle its at 18ish vacuum