Opinion's on a DownPipe!
ok heres a quick definition off the net:
In closed loop operation the ECU uses one or more oxygen sensors as a feedback loop in order to adjust the fuel mixture. This gives the name closed loop from the closed feedback loop. The ECU wont run in a closed feedback loop all the time, so open loop is used to describe the operation of the ECU when the mixture is not being adjusted in this way (usually when the engine is cold or when running under high load).
In closed loop operation the ECU uses the oxygen sensor to tell if the fuel mixture is rich or lean. However, due to the characteristics of the oxygen sensor it cant tell exactly how rich or lean, it only knows that the mixture is richer or leaner than optimum. The ECU will enrich the mixture if the oxygen sensor shows that the mixture is lean, and lean the mixture if it looks rich. The result of this is that the mixture will swing back and forward around the stoichiometric point.
basically due to the fact the OBDII o2 sensors need to be heated before they start to work properly.... so what happens during the startup process the computer usues a pre-programmed fuel trim (open loop) when they heat up and begin to function properly the ecu uses the data from the sensors to adjust the fuel trim (closed loop) hope that helps.... any other questions just ask.....
In closed loop operation the ECU uses one or more oxygen sensors as a feedback loop in order to adjust the fuel mixture. This gives the name closed loop from the closed feedback loop. The ECU wont run in a closed feedback loop all the time, so open loop is used to describe the operation of the ECU when the mixture is not being adjusted in this way (usually when the engine is cold or when running under high load).
In closed loop operation the ECU uses the oxygen sensor to tell if the fuel mixture is rich or lean. However, due to the characteristics of the oxygen sensor it cant tell exactly how rich or lean, it only knows that the mixture is richer or leaner than optimum. The ECU will enrich the mixture if the oxygen sensor shows that the mixture is lean, and lean the mixture if it looks rich. The result of this is that the mixture will swing back and forward around the stoichiometric point.
basically due to the fact the OBDII o2 sensors need to be heated before they start to work properly.... so what happens during the startup process the computer usues a pre-programmed fuel trim (open loop) when they heat up and begin to function properly the ecu uses the data from the sensors to adjust the fuel trim (closed loop) hope that helps.... any other questions just ask.....
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From: Merrick L.I.
ok thanks that did help a lot. now my only question would be if the closed loop runs off your sensors then why would you want that to be able to pass inspecton? would you want an open loop so all your mixtures are fine by the computer? then wont it deff pass inspection?
i got a few more questions lol.
how is ur trans am cattless and no CEL and passes inspection?
id love to run a catless DP but i dont need the bullshit with emissions.
cars come stock with closed loops but use an open loop when the motor is cold or under pressure right?
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From: Merrick L.I.
ok sweet. thanks for all this info man.
i got a few more questions lol.
how is ur trans am cattless and no CEL and passes inspection?
id love to run a catless DP but i dont need the bullshit with emissions.
cars come stock with closed loops but use an open loop when the motor is cold or under pressure right?
i got a few more questions lol.
how is ur trans am cattless and no CEL and passes inspection?
id love to run a catless DP but i dont need the bullshit with emissions.
cars come stock with closed loops but use an open loop when the motor is cold or under pressure right?
the trans am is tuned so it passes the emissions test.... as long as tghe inspector doesnt look under the car and see no cats Im golden ( I use a shop where I know the owner and he specializes in f-bodys) and yes the motor will use an open loop when cold due to the fact in take a few miles for the 02 sensors to heat up and become acurate.....
but if he uses the muffler sniffer im fuc***!
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From: Merrick L.I.
yup.... and the chances of the "sniffing" your car are slim to none.... the shops only get like 5 bucks for an inspection.... in order to do a sniff test they have to strap it to an inspection dyno.... run it at 60mph and do a few other tests wich take about 45-60 min including the time it takes to secure the car.... a typical OBDII inspection takes 10 minutes.... answer a few questions on saftey ( if the belts brakes work ect) hook up the obdII scanner and bam..... inspection sticker is printed.... (provided the car passed of course)
Found this CIA catted downpipe on Craigs List for $200..damn good deal.
2008-2010 Chevrolet Cobalt SS/TC aftermarket Downpipe
2008-2010 Chevrolet Cobalt SS/TC aftermarket Downpipe
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