bitween_snow

Hi everyone. I have a 2002 RSX Type S with about 140K Km on it (87.5K miles). Recently the check engine light came on and I took it to my mechanic and he hooked it up to his computer and said it shows 3 codes one of which was a malfunctioning O2 sensor. The other two I do not remember and he did not take note so he does not remember. Anyway, he reset the codes to see which one comes back on and when he did only the O2 sensor came back on. I was in a hurry and could not get it replaced that day and he said it is ok to drive a bit so I went about my work and drove about 200 km (125 miles) and then decided to put that Guaranteed to Pass stuff in it and refuel to get it ready for emission test. After driving about 100 km (65 miles) on the new tank, while I was turning the car turned off and every time I tried to turn it back on it choked and did not work. so I pushed it aside and waited for about half an hour and then tried again and it worked fine. I did not think much of this and drove another 50 km and the same thing happened again, but no matter how long I waited it did not turn back on. So I got it towed to my mechanic and left it overnight. In the morning, when the mechanic tried turning the car on it turned on fine however it would die when randomly when idling. So he replaced the O2 sensor and the check engine light went away and there were no other codes. So, we assumed it is fine. Indeed I rode it around the shop for about 2 to 3 Km and it was fine but as soon as I got into the highway it started choking this time while doing 80 km/h (50 mi/h). I got out of the highway but did not make it to the shop. the car turned off at a turn and did not turn back on. so I got it towed again to the shop and there is not engine light but still the car does not stay on. keeps choking. What could be the problem? It is driving me mad and my mechanic is not sure what could be wrong as it is not throwing any codes. Any help would be much appreciated.

On a slightly related note, what is the difference between the before and after O2 sensors for this car? Is the only difference the size of the wire or are the sensors different also? The reason why I ask is that I may have installed an after sensor in place of the before sensor but the leads were the same so I did not think it would be any difference.

bitween_snow

Oh by the way, I have the following mechanical mods on my car related to the engine:

DC Racing Header with Greddy Catback Exhaust system
AEM Cold air intake

Thanks.