ok i have a 98 ls1 car hesitates when stepping on gas pedel then goes car read codes p0135,p151 im going check fuses now but what o2 sensor i buy and how many i have rear deleted and egr if it both fronts let me know trying to get ready for dyno tune 2 morrow thankx for any help

 

Both are front 02 codes:

P0135 is Bank 1, Sensor 1 - Heater
P0151 is Bank 2, Sensor 1 - Low Voltage

 

ok i changed them

 

same problem still runs the same could the plugs need changing now?any help please and how can i tell if a relay is bad????all fuses good how do i check relays

 

ok what is heater?