Stubborn P1273 Code will not go away.

[volcomcy]

Hello, I have a 2005 350z touring non Revup. I keep getting the annoying P1273 code (Air/Fuel Ratio sensor 1)
The mods are:
Megan test pipes
Kenetix V+
Stock intake tube with stillen intake filter after MAF
Catback exhaust with no leaks
The car is not tuned

I went ahead and replaced the MAF sensor and installed high flow cats. The code came back after about 30 miles of driving, It typically comes on at little to no speed. Should I replace the B1 S1 O2 sensor? What else may cause this code that I should look for?

My inspection expired 7 months ago and I really would like to avoid a ticket.

I swapped my test pipes out for a set of old high flow cats and this is the result after driving
P2173 (A/F ratio)
P0159 (o2 slow response B2S2)
P1166 (Heated o2 S2)
P1167 (Heated o2 S2)

I recently replaced the B2S2 o2 sensor about 100 Miles ago.

[evildky]

You answered your own question, Test pipes. I've heard of people using spacers on the second O2 sensor so it doesn't get a full read. Me I don't like having black crap on my bumper so I'd look at a stock or high flow cat.