HT4100 4.1, 4.5, 4.9 Discussion, error E46 where to start? in Cadillac Engine Technical Discussion; I'm getting an E46 error (fuel imbalance) and was wondering where a good starting point is for trying to diagnos ...
any clue as to the year and model and engine....????
Let's see...it must be either a 1990 4.5 or a 1991-95 4.9 and in a Seville/Eldorado to have two O2 sensors.....
First thing is to check the O2 sensors for connection and activity. Do you know how to use the onboard diagnostics to look at the O2 sensor activity???
Take the fuel rail hold down bolts out and lift up the rail so that the injectors clear the intake ports. Turn on the key to see if any of the injectors are dripping/leaking when the fuel pump runs to pressurize the system.
With the engine idling, pull the vacuum hose off the fuel pressure regulator. Watch the vacuum nipple on the FPR for any sign of leaking fuel for several minutes. There should be none.
Clean the EGR tubes. Hold the throttle blades wide open and look down the throttle bores. See the two tubes sticking up at you from the floor of the intake manifold. Those are not supposed to be full of carbon. Rod them out with a piece of stiff wire until they are clean and clear for the EGR to flow.
While you are in there, spray the bore of the throttle body with carb cleaner and scrub the bore and the backside of the throttle blade with an old toothbrush to clean the deposits off the bore below the blade. Won't affect the code but should be done. Disconnect the negative battery terminal for 30 seconds when you clean the throttle body to reset the idle learn offsets.
Wait a minute....I remembered your earlier posts. You have an 88 4.5 Deville, right???
You cannot have a code E46 in a Deville. They only have one O2 sensor and do not do the cylinder bank offset check and that test was not done on a 4.5 TBI engine anyway.
You must mean F46....which has nothing to do with the engine. It stands for the AC system being very low on refrigerant. You likely need to have the system recharged as it has likely leaked down at this point to where the low refrigerant code is set. That was an R12 system so you will need to find a shop that can charge it with R12....or take the time and $$$$ to convert it to R134a. Perfectly doable....but it takes some time and $$$$ also. You will have to evacuate and flush the sytem, change the accumulator, evacuate the system and charge with R134a...