Cuase of P0135 & P0141

[blackhatch96]

P0135 & P0141 02 sensor heater circuit malfunction Bank 1 Sensors 1 & 2 help troubleshoot questions

OK so I just bought a black 96 hatchback dx 5spd for a smidge over 2 grand today It has 151,700 miles on it and a few aftermaket bits, which include off brand - OBX or magan racing 4-2-1 two piece header and a short ram intake which is also I suspect OBX or ebay junk! Also white 17x7 TSE Revo's with fedral tires I think. Now I new there was a few things wrong with it when I bought it! But for the price I feel it was a "good" investment, not GREAT, but good!
I plugged in the OBD-II scanner and the above mentioned codes flashed (P0135 & P0141). I have read a few places that with the aftermarket header on, an EX highflow cat should be used in place of the stock OE unit after the collector and before the resinator on the mid-pipe. Also to extend the 02 wires to reach. THERE IS NO CAT SO I have to pick one up, I wanted to know why I am getting CEL for both sensors are the both bad or whats the deal! Should I put in a cat and see what happens or should I start some where else!

[1qwkEF]

IF its a heater circuit problem then they will both need to be replaced reguardless if there is no cat. It means that when ur car is running in closed loop when u first start it up the heater circuit is not turning on due to broken element or something similar. Very common on every car manufacturer.