I had some minor front end damage after tapping a guard rail. They had to pull the radiator,evacuate & recharge the AC & R&I the alternator to pull the rail just fwd of the radiator & front clip. I had some air in my cooling system & brought it back & my AC needs more refrigerant.
Now my 2005 is losing HP. It slowly is pulling less and less. I'm not sure if it's an accessory issue or what. I thought I heard a minor valve tap or knock at high rpm's. My car only has 15k miles. It flawless. No drive-ability issues. I'm afraid something is causing this thing to knock retard. I also just put in a new system. It is all professional though. A Zenclosure, a monster Brutis in the compartment behind the driver where the factory bose 10 would be & a Kenwood DDX 900 series with two JL W3's.

I was thinking lack of spark from power from the amp or maybe one of the accessories was causing a draw that wasn't put on correctly..... I'm stumped. Do I need to go get a tune to make sure my car's #'s are where they should be?? Should my RWHP be 250-270? This car was a hard find. All black coupe manual with 12k miles & I only paid 17k.

I do have Avante Garde M310's 19X9.5 & 19X11 in the back but it pulled hard when I put them on still. I'm 800 miles since the repair & I've noticed it in the last 300. I just put Eibach's on but it actually softened the ride. So I got some Stance Pro Comps that will be on soon enough. With the car now lifting with the softer springs instead of squatting I thought maybe that would translate to a lack of pull. Any thoughts?? Thank you.

 

How do you know this fact? Dyno test? Compression test? I could take a stab in the dark but it would be just that - a guess. Visit Nissan a run a complete diagnostics.

 

a Dyno would be cheaper & safer than a dealer diagnostic. The most dangerous thing we can do to our cars is allows "technicians" to mess with it. I dyno is the safest root. I don't want some drunk on a bad day pulling my plugs etc. Unless this function can be obtained through the OBD??