3 ms·
ERG is just a pipe from the exhaust to the intake with a valve. Compressing and carefully releasing would be much more complicated and very much a not normal wa
by s1lver 11y ago
ERG is just a pipe from the exhaust to the intake with a valve. Compressing and carefully releasing would be much more complicated and very much a not normal way of lowering exhaust temperature to reduce emissions.
- spydum 11y agoYes, on second thought, they probably confused secondary air injection ( https://en.wikipedia.org/wiki/Secondary_air_injection https://en.wikipedia.org/wiki/Secondary_air_injection ) with EGR. It's very possible they were explaining secondary air, which doesn't compress exhaust gas, but does inject air into the exhaust gas to help burn more efficiently (not clear on the mechanism, I always thought it was a method to improve catalytic converter efficiency at startup).
- jhallenworld 11y agoThe usual failure mode is that it sounds like a loud vacuum cleaner for ~90 seconds after cold start up.. not sure about clunking.
- Alupis 11y agoI owned an RX-8 which had an air pump (secondary air injection) which would come on for about 30 seconds on a cold start. When the pump started going out, it would make a metal grinding sound. Drove like that for a few years until it quit working, and didn't think anything of it until SMOG time - $600 for an air pump which works for ~30 seconds...
- heywire 11y agoExactly. Cheverolet Trailblazers are well known for this (I owned one and had to replace said air injector)
- lutorm 11y agoI think the idea is that cold engines run rich, so injecting air into the exhaust gives the unburnt fuel a chance to combust in the exhaust pipe before getting to the catalyst. This is good for two reasons, first, it heats the catalyst up faster, which is good, and it also reduces the amount of unburned hydrocarbons.