Will my Oxygen sensor get screwed up with this setup?

rithsleeper · 04-29-2008, 10:50 PM

87' C4, if I replace my Cat with straight pipe, and have Y-pipe cutouts infront of my mufflers, when I open them up will the oxygen sensor mis read?

I ask because I mounted a y-pipe cutout in front of my cat on my Cadillac seville and when it was open the computer just dumped fuel into the engine running it way too rich.

94LT1VETTER · 05-02-2008, 01:16 PM

Should be ok as long as you're after the first set of 02 sensors.
If you've only got one set of 02 sensors, then be sure your cutout is after the sensors. The tailpipe will draw a vacuum and mix fresh air in with the exhaust leaving the engine, causing bad reading and a/f corrections.
If you've got the 2nd set of sensors too, just get 02 simulators. All's they are there for is so the ecu thinks the cat/s is/are there and functioning properly.

BLOWNBLUEZ06 · 07-02-2008, 05:30 PM

Only obdII has rear sensors. OBDII began in mid 1995, so you are OBDI and unless you create a situation that allows fresh air to get to the O2 sensors, that is not your problem. When you say "dumping fuel" do you mean that it smells rich? When you remove the cats, you will smell the fuel. Sometimes a great deal.