Please Help

I currently helped a friend of mine install a header that he bought from his friend, I am not sure where his friend got it from but it does not have an EGR Port I am guessing that it is a JDM or european header, WE have it all installed and we just removed all of the EGR components and Fabricated an egr block-off plate, Nor did it have an O2 sensor port, and we are replacing the rest of the exhaust with high flow CATCO cat and A Wide Open Magna-Flow muffler, At this point there is no O2 sensor hooked up, Car cuts down at around 3000 RPM my guess is that it is the the lack of O2 Sensors, Do both sensors need to be hooked up or just one? If only one needs to be hooked up which one Manifold or CAT? Is it Safe to Block off and Remove the EGR system all together? If so What all needs toi be removed besides the EGR, BPT, and plugging up the one vacumn line? Anyone's help or input in this matter would be greatly appreciated.

Possibly some of the more experienced people will have a better idea of what is needed but here goes my two cents worth.
The easy solution is to drill out two hole for the sensors and weld in (or have welded in if you do not have the equipment or skills) new bungs for both sensors. It is really a small job and fixes the problem correctly.
The only downfall of this is that you may have to remove the header again but I have learned to do it right the first time and then not have to worry about it later.

EGR can go. You did the correct thing with the block off. Definately plug the vacuum line.

Just drill a hole and weld in a bung. www.atpturbo.com has them or you can do what I do. Take the O2 sensor to your local hardware store and match it up with a nut. Then weld that in. I did it for my wideband and my stocker. Works like a charm. Good luck.

ALright WE have the exhaust in and the #1 O2 sensor has been moved to after the flex and before the cat on the downpipe, and the second one is in, we then reset the computer and took it for a ride, IT pulled ok through first and then in second somewhere around 5500RPM we got fuel cut, felt like the rev limiter, then after that it cuts down at
2500 RPM feels like it is hitting the rev limiter. EGR system is completely removed The only thing that is left is the Sensor that all of the EGR Vacumn lines goes too, there are three nipples on that sensor, one on the bottom that goes to the throttle body right before the butterfly, then there are two nipples on top, the top nipple is not attached to anything, normally it is attached to the BPT, the second one to the top of the sensor is attached where it normally goes on the intake hose, after the MAF and before the Throttle body. What the heck is going on. why is it cutting at 2500RPM other than because the ECU is cutting fuel. why is the ECU cutting fuel, Is it because the O2 Sensor has been moved so far down stream? or does it have something to do with the EGR system and the Charcoal cannister that is not hooked up, or does it have something to do with the EGR vacumn sensor? Please help???????

Does it feel like dead spots? I expireiced the same problem for a while and found it to be a combo of the TPS being adjusted incorrectly and bad plug wires.

The O2 sensor should be put in one of the runners on the exhaust. If it is too far from the engine, it takes a while to heat up and give accurate reading.

Just plug all those vac lines running to the BPT and EGR.

dude, what will we do with out nissanfanatic?
i mean, SR20detpower new allot too but he is not around anymore...

sorry dude, i know what u did is right... i don't know why its not reving past 5000rpm? did u weld the O2 close to the motor? reset the ECU?

dude, what will we do with out nissanfanatic?
i mean, SR20detpower new allot too but he is not around anymore...

hahahaha. Thanks. It means a lot. But what would I do without you guys? I would not be able to help anyone.

Did you figure the problem out? I have recently purchased a 240 from a salvage yard to build into an ice racer but some under hood parts have been scavenged already. I am now having the same problem where the car cuts out at about 2500 RPM.
If you found a solution let me know as it may give me a starting point to chase down the problem.
Thanks