So I got the service now message on the car today, when I went into diagnostics, I found E046 ( air system fault) and E049 (right to left bank fueling problem) is there a common cause for these with a general fix? .. I thought I'd ask before I go thru the entire diagnostic procedure..I was going to just clear the codes and see if they return, the car seems to be running great otherwise...



thanks, Matt

Its seeing a fuel delivery imbalance left to right. Try injector cleaner LUCAS) and erase codes.

i been getting those for 2 years on one of the '88s, i gave up trying to find the problem. it hits when it is cooler weather .. when it is hot, i dont see them

so, i make sure i SMOG the car when it is 95F+.
I threw parts at it, per advice of all the "experts" to no avail.


if you find the issue, let me know.

One other possibility: a lazy oxy sensor could be slow at monitoring the fuel delivery on one bank. So enter diagnostics and compare the right vs the left oxy sensor for speed of switching. They should be close in readings and switch in less than one second, rich to lean.

Just a little update, I cleared the codes & I over treated the fuel system to some techron ( 2 bottles then filled up) each is supposed to do 16 gallons. I've been driving this car more then usual lately,partly testing to see if the code comes back, and partly because the weather is SPECTACULAR ( 72 and sunny) . Anyway, car is running fine, just as before there is a tiny, slight miss of sorts, but almost not noticeable.. BUT.. I did notice that my gas mileage has dropped, on an all highway trip yesterday of about 80 miles I was only averaging 17 ish according the the computer.. could this be because of all the fuel system cleaner still in the tank? does it burn a little differently? just wondering..I'm usually around 21 - 23

i bet when the cat trows those codes EO49 & EO46, you got a near full tank of fuel.