|Similar Projects: |
|Submitted Tags: |
Tricking your car's computer into thinking everything is A-OK with your catalyst. Much cheaper than buying real O2 sensors.
First: It is illegal to tamper with ANY emissions control system in your car in the United States.
What: Simple oscillating circuit using the very common 555 timer IC (it does not have to be the CMOS version, so you can save the $1 if you buy new).
Why?: The OBDII P0421 (Warm up catalyst efficiency below threshold) code popped up. My dad thought he would be nice and just replace my catalytic converter (cat for short). Well, its the downstream O2 sensor that is bad (that's the one after the cat)... A New sensor costs between $60 and $150+ This device cost me less than $5 for EVERYTHING including a nice little case.
How to make: No, I'm not going to supply the circuit diagram. You can find it online somewhere - but its a basic astable oscillator ;) And because it is illegal to use, I don't want to bring trouble to supersoda or its creator(s).
It works! I was able to fool my car's ECU into thinking everything was A-OK. However, I bought an OBDII scanner from harbor freight ($40) so I can read/clear codes quickly (this tool was very much worth it). No need to hack my ECU harness when I can just wait until I have money for real car parts.
Yes, if you remove your cat and replace with a test pipe for "off road use only" - this will effectively fool the computer.
I swear... I have done more than auto hacks and projects :P But I don't want some kid blowing a hand off if I explain how to make ammonia tri-iodide from household products - and unless I have something really unique on a pneumatic cannon... we're pretty covered already :P