I recently got a 2015 IS 350, standard (not F sport package). I love that the exhaust is a little bit "throaty". I like it a lot more than the ES 350 I traded. Is anyone aware of gentle mods for the exhaust that might make it even more throaty with a little growl at the top end? a new exhaust system? thoughts?
By adrian torres
My 1997 LS400 has had a drop in MPG from around 20mpg to 15mpg after my Lexus was serviced at the local dealership. I had to replace a damaged driver side heat shield that was dented. The dealership had to "drop" the exhaust in order to replace the shield. After that repair, my mpg had dropped and never recovered. I took it back to them, and they could find nothing wrong. I tried to drive during different times of day, commute routes, etc. and they are all result in the same low mpg. However, highway mileage is stayed at 25mpg when I drive on the interstate at a constant 65 mph.
I mentioned to them the water temp sensor that everyone in the forums point to, and the dealership did not think that it was the cause, since the drop occured after they serviced it. They also stated that the exhaust drop would have nothing to with a drop in mpg. They tested the o2 sensors and they were working fine, and there is no engine light. They stated that the car was fine, however they could replace the sensor for $250 but would not recommend it as it would not solve the problem.
I wonder if the rear o2 sensor is sensing a air leak, if the dropping the exhaust caused a seal to break and this is causing the car to run rich.
I am running out of ideas and the drop is causing my fuel costs to increase 25%.
Any ideas or suggestions?