4 ms·
I mean, I can tell you first hand how easy it is to trick an OBDII emissions test just by messing with the ground wires associated to the O2 sensors and bam, yo
by spacecadet 3y ago
I mean, I can tell you first hand how easy it is to trick an OBDII emissions test just by messing with the ground wires associated to the O2 sensors and bam, you have different values being report by O2...
- bigallen 3y agoWouldn’t the state emissions system throw an error if a vehicle’s O2 sensor was reading 0/null?
- spacecadet 3y agoI cant speak for very recent systems, but they are not binary, the ECU expects a range of voltage readings...
- sokoloff 3y agoEarly OBD2 downstream O2 defeats were a simple astable timer (and, for some cars, a power resistor to simulated the heater draw). The state testing in most states now is ‘make sure the ECU is reporting “READY” and has no emissions-related codes set.’ Since the advent of OBD2, it’s become rare for a state inspection to run the vehicle live for the purpose of emissions testing. Plugging in the OBD2 scanner is way faster, cheaper, more convenient, safer, and easier (albeit slightly) on the car than using a dyno.
- TylerE 3y agoNotable, however, California, the largest vehicle market by some margin, still requires sniffer tests.
- AvocadosNombre 3y ago* for vehicles model year 1999 and older, not more modern ones.
- CableNinja 3y agoOnly on older cars, which do not have OBDII. OBDI and before that require a sniffer. OBDII has enough sensors that the sniffer isnt needed. Am in CA, and only my foxbody ever got a sniff test. All of my other (newer) cars, the sniffer wasnt used