Search the Community
Showing results for tags '4.9'.
Could use some help/advice on diagnosing an E046 trouble code for a '92 Eldorado with the 4.9 liter engine. I also failed my last smog check because of excessive NOx, btw. I'm thinking the two things are related. E046 is the the 'Left to Right Bank Fueling Difference' that will produce a Service Engine Soon light. My E046 is the single current code but the SES only comes on intermittently. My due diligence of Googling other people's experience with the E046 on this and other forums has been a bit disappointing. Many of the E046 complainers don't seem to use a Factory Service Manual for diagnosis, and most of the E046 threads I've seen have the guys replacing O2 sensors and fuel injection parts without really taking a more scientific approach (i.e. not throwing parts at the problem and hoping it will go away). Apparently the O2 sensors can be bad and produce an E046 without spitting out a more O2-specific trouble code. Anyway, the fault tree for E046 can be found on my attachment IMG_0379.jpg with some more info on E046 found in attachment IMG_0385.jpg Going through the steps of the tree, I am witnessing the ED35 (Right O2 sensor cross count) bouncing around from 0 to a high of 34, while the ED34 (Left O2 sensor cross count) varying between 0 to a high of about 24. These values do not seem to linearly increase as the car accelerates or travels at a higher rate of speed. Even just idling in Park in my driveway can produce non-zero cross counts. What should I do now? I have seen previous posts with differing opinions, e.g. the actual numerical value doesn't matter, it's the frequency of the numbers changing, the 0 value is no good, a high number is better, etc. and so forth. Some previous posters don't seem to have a really good grasp of what 'cross count' really means (me included). I'm taking an educated guess that if the cross count reading is '5' as an example, this means the O2 sensor is dictating 5 changes per second from a rich to a lean burn. Is that correct? So I have many more questions than answers, is there somebody out there that can help me with this dilemma? I feel that just blindly replacing O2 sensors as historically been done might be my last resort otherwise. Thanks, cadillac fellas.
95 deville 4.9 stalls at idle no codes set, ICS replaced - no change. Exhaust system replaced including catalytic converter. Started to remove EGR, discovered that it ran much better WITH a vacuum leak. - the brake booster hose was off. Any suggestions? Thanks