SecondCor521
Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Hi all.
1993 Lexus GS300 with 180K miles.
The only symptom is a sudden loss in fuel efficiency. I'm still working on the measurements, but it's gone from getting ~20-22MPG to getting about ~10MPG.
There are no other symptoms. No rough idle, no loss of power on acceleration, no check engine light, no other dashboard lights, no fuel smell any time.
It does not seem to lose fuel when parked in my garage.
I believe the tire pressure is good, the brakes are fine (no pulling to one side), the air filter was changed recently. Spark plugs and wires were done 2 years / 30,000 miles ago.
The idle RPM is normal. There are no noises and no fluid leaks.
The main suggestion that makes some sense that I've heard is O2 sensors going bad. The puzzling thing is that everyone thinks this should throw a code and trip the check engine light.
Oh, the check engine light itself is working. It comes on with the key in accessory and goes off when the engine is started, just like it is supposed to.
No fluids leaking. Power steering, coolant, and oil all changed recently.
Engine isn't overheating.
The problem cropped up suddenly, and it also happened almost exactly at 180K miles. I wondered if Lexus has some sort of computer thing that trips at that mileage to force you to take it in, but I kinda don't believe they would do that.
I tried taking it to Autozone to read the codes, and they weren't able to read the codes at my nearby store. The code reader couldn't find the vehicle, whatever that means. Maybe try another store?
I have an appointment to take it in next week, but I'm hoping you fantastic diagnosticians can help with suggestions or ways to narrow it down. I'm a tad concerned that if I bring it in with the above information that they'll just have to shotgun-replace parts that could be bad, since it seems like this might be a "process of elimination" kind of issue.
1993 Lexus GS300 with 180K miles.
The only symptom is a sudden loss in fuel efficiency. I'm still working on the measurements, but it's gone from getting ~20-22MPG to getting about ~10MPG.
There are no other symptoms. No rough idle, no loss of power on acceleration, no check engine light, no other dashboard lights, no fuel smell any time.
It does not seem to lose fuel when parked in my garage.
I believe the tire pressure is good, the brakes are fine (no pulling to one side), the air filter was changed recently. Spark plugs and wires were done 2 years / 30,000 miles ago.
The idle RPM is normal. There are no noises and no fluid leaks.
The main suggestion that makes some sense that I've heard is O2 sensors going bad. The puzzling thing is that everyone thinks this should throw a code and trip the check engine light.
Oh, the check engine light itself is working. It comes on with the key in accessory and goes off when the engine is started, just like it is supposed to.
No fluids leaking. Power steering, coolant, and oil all changed recently.
Engine isn't overheating.
The problem cropped up suddenly, and it also happened almost exactly at 180K miles. I wondered if Lexus has some sort of computer thing that trips at that mileage to force you to take it in, but I kinda don't believe they would do that.
I tried taking it to Autozone to read the codes, and they weren't able to read the codes at my nearby store. The code reader couldn't find the vehicle, whatever that means. Maybe try another store?
I have an appointment to take it in next week, but I'm hoping you fantastic diagnosticians can help with suggestions or ways to narrow it down. I'm a tad concerned that if I bring it in with the above information that they'll just have to shotgun-replace parts that could be bad, since it seems like this might be a "process of elimination" kind of issue.