I've used the cheapest sensor I could find at the time, I think it was $120 or so and have over 11k on it and it still works perfectly. I think its hit or miss with them. I have a theory though. I'm wondering if the resistor built into the plug has to match something in the ecu, in other words does the sensor have to be calibrated to work correctly? There is a tolerance built into resistors and that could also make a difference? (note all the question marks - I'm guessing here) Does anybody feel like checking the actual resistance of their resistors and posting? Maybe they're all the same and I'm on crack, but if we find differences between them, it MIGHT account for why some people are not having problems and others are? I just measured mine and it reads 29.97k ohms. Anybody with a vx PLEASE measure your O2 resistor value and post up. At the very least, those of you having problems might want to compare the resistance of your old sensor and compare it to the new one.