i just wish this thing would throw a code or something to give me a hint at what could be wrong, i know it had the cat below efficiency but it was doing it way before that, may even be what destroyed the cat too.... i dont know lol i kinda am narrowed down to the throttle position sensor, iat sensor and coolant temp sensor but again thats firing the parts cannon

 

Much better. Cruising intake temps are good. The high intake temps for long periods of idle time wont affect your gas mileage like that. It's only if they stay high. As greasemonkey said, are the o2 voltage numbers fluctuating while it's running? Can the scan tool show a graph of the info?

 

If the O2 sensors weren't ranging properly, I would think that would immediately show up in the fuel trims.

I'm curious if the fuel system is switching to OPEN (FUEL SYS 1) when it should not be due to bad readings from the TPS. Especially during acceleration, as this would cause a lot of rich running. Based on my digital dash, I think the fuel trims immediately go to 0% when the fuel system switches to OPEN loop. So its not always obvious when just monitoring the fuel trims. It typically takes a lot more throttle to accelerate under load (actually driving) then when simply increasing to 2000rpm in the driveway. So the TPS might have a problem that isn't obvious in the driveway. Can you monitor the scanner while driving while keeping an eye on the CLSD/OPEN status of FUEL SYS 1? It is normal for it to go to OPEN when decelerating (foot off of throttle) and when aggressively accelerating, but during normal acceleration and driving it should be CLOSED most of the time (like 99% of the time).

 

hmm ill have to look at it tomorrow, i may purchase a bluetooth dongle to monitor more things and with charts as this one doesnt have a chart it only updates every second.

 

Neither O2 sensor should read 0.1 volts. Graphs may shed more light on this, but in the absence of any other abnormal findings, you may need both sensors replaced. I believe P0420 can be generated if S2>S1 (cat isn't utilizing O2), so f you're seeing a lot of 0.1 volts out of S1 that could explain the issues.

 

the o2 sensors? but theyre brand new ntk ones....

 

Let's take a look at the graphs. Should look something like this with a bluetooth sender:



If your scanner is reading mean, then there's definitely an issue, but right now it seems you have too many 0.1 volt(ses) to be a coincidence.

 

Meanwhile, pop them things out and see what they look like. At 6.3 MPG perhaps they're encased in carbon.

 

bah i dont have a bluetooth thing yet lol but even after 300 miles? thats how much i drove on these new ones and while the issue did improve a little its still there. and you think the voltages dont look right? ill have to look later for now im tired, being woken up at 4:30 am to drive 130 miles away to jump my moms car cause it died isnt my sort of thing and am now going back to sleep lol.