O2 sensor/cat question
Hey guys, I have searched but havent really found a real answer to this question. I also have some pics to show what im talking about better anyways. So I have three cats, and 4 o2's. There is 1 cat in each down pipe, and 1 last big cat. The o2s are in the down pipes before and after the first cats. There are none right before or right after the last cat. That makes me believe that the last cat is "unmonitered" I guess you could say. Well, what I want to do is possibley remove that last cat, it is a 2 in 1 out, and add a di/do flowmaster. I have already had a flowmaster on this truck once but it wasnt quiet agressive enough for me so I had it taken back out and had a Y put back. I have straight duals Y'ed from the cat back. I was just wondering if I ditched the last cat and had a di/do put on, will I get a check engine light? I really don't see any reason for it since the o2s only seem to be monitering the first cats in the downpipes. Here are some pictures I have taken to show more of what I mean.
Left side first o2
Left side second o2
Right side first o2
Right side second o2
As you can see in the last pic, that is the last o2. Like I said there is 1 o2 before, and after the first cats. There are none right before or after the last one, which is why I don't think it will affect the check engine light by removing it. Im not asking for a lecture on why I should leave it there, I just would like a simple answer to the question. I do plan to leave the other cats there.
Any help is appreicated,
2008 Ranger FX4 - Vista Blue, Extended cab 4-door, 4.0L, auto.
2004 Ranger Edge, Sonic Blue, Regular cab, 3.0L, 5 speed. Many mods.
Last edited by mj550; 09-16-2007 at 10:50 AM.