my swap lacks the secondary 2 sensor and im not ghetto rigin a 2 wire one sensor bs, my shop has the dc 421 and is going to weld in a second bung.

question
1)doenst the primary o2 go in the new bung, and where do u weld this
2) doesnt hte 2nd o2 (the added one one for b16a) go in the pre existing hole on the dc,

3) what works for a 2nd o2 sensor i know primary is 90-93 teg or is it 88-91 ef si?

thanks

FUEL

 

use 2 stock 88-91 SI O2's, with both bungs in the middle of the downpipes.

 

I would have bungs welded in the "2" part of the 4-2-1 and plug up the one that was already on the header with a bolt.

 

for part for cylender 1 and 3 is that primary or secondary (vtec) and ure sure both are 88-91 si?

thanks