help!!!!!! false codes?
help!!!!!! false codes?
My ecu gave a code 45, and it seemed to be running rich because i there's a strong gas smell from the exhaust when i start the car cold. I removed the fuel rail with the injectors still on and turned the iginition on. nothing leaked . no dripping gas from the injector spraying part (?). I did a search and this guy got a code 45 also, but it turned out to be his fuel pump. How does the ecu know what code to put out? are the codes more of a guideline to where to look (in my case, the fuel system)? My car wont pass emissions because of high CO emissions at idle. above 2.5k rpm is fine though. I changed the water temp sensor and the ecu is giving code 45. Thanks everyone!
if its got high co at idle it is definitly running rich as the code 45 indicates. the code is determined by the o2 sensor. the best way to see what the o2 sees is with a dso (digital storage osillscope) a volt meter with high impedance will work too if the reading is extremaly high. the o2 should sweep back and forth from low to high volts it ranges from 0 to 1 volt. if the reading stays high you are getting to much fuel. but a bad o2 could cause a problem so test it . to test it place your volt meter or your dso on it . first check to see if it goes lean by creating a vaccum leak try to pick a none vital vac line like to heater controls try to stay away from solonoid vac hoses since it could alter your readings. and definitly dont mess with the fuel pressure regulator it will cause it to go rich if you pull that. what you should see is the voltage from the o2 to drop below .175 volts. if good go to next test make sure it goes rich do this by squirting a little carb clean into the air cleaner or disconnect and PLUG the fuel pressure reg vac line. it should go above .8v you have to moniter these readings imediatly when creating the vac leak or richen condition because the system will compensate for it and try to get the sweep back. if those to tests turn out no good you should replace the o2 and recheck. if those are good there is one other test for an o2 but you have to have a dso to get accurate results.
the vaccum leak may need to be significant to get the o2 to drop. so if a small vac line doesnt do it try the brake booster vac line . but try to only allow a restricted amount of leak since a full booster leak will stall the engine out . try to just lean it to the side while holding it on the booster or vac port