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I wanted to provide a follw-up post regarding my original problem. I took my car to a local MIdas dealer, who told me that I needed to replace my MAF sensor, which I did, but that did not fix my problem. Midas then diagnosed low fuel pressure (2 psi) at my new fuel filter port and told me that I needed to replace my fuel pump, which I did, but that still did not fix my problem. I then gave up on Midas and took my car to my local Lexus dealership for more diagnosis. After three hours of diagnostic time, they determined that my fuel pressure regulator (FPR) had failed (due to human error - the air intake nozzle had become bent and thereby damaged the internal components in my FPR. Interestingly, my FPR passed 4 of the 5 diagnostic tests that Lexus had performed on it. They ended up removing the FPR and then saw via visual inspection that the FPR was physically damaged. Also, I was getting no black smoke out of my exhaust system (typical when an FPR fails), and FPRs rarely fail on mid-90's Lexus and Toyotya models, so this was definmitely an extremely rare failure mode. Just glad that my problem is finally fixed! The FPR is extremely easy to remove, so it is well worth your time to visually inspect it when you are trouibleshooting your fuel system.

I'ver spent much time over the last few days trying to diagnose and fix my problem without success. I have removed and thoroughly cleaned the throttle body and IAC Valve with Throttle Body Cleaner (both were very dirty with visible carbon build-up and had never been cleaned before). Also, I cleaned my MAF sensor with Electrical Cleaner. I also replaced my fuel filter, since it had never been replaced by the previous owner. I've also checked all of my hoses and gasket connections for air leaks. Currently, the car will start (although it takes 3-4 seconds in time) and it idles smothly at about 900-1000 RPM. However, the car experiences sluggish acceleration (especially in lower gears and and when driving up hills. In higher gears it seems to run better but still experiences some sluiggishness. After driving the car locally for about 35 miles, I am only getting a single error code: P0170 - Fuel Trim Malfunction (Bank 1). Also, I replaced my Rear Manifold O2 Sensor about 2 years ago, so I don't think that is the problem. According to the online reading that I have done, MAF Sensor failures in 1995 ES300 modles are realtively rare, so I tend to think that also is not my problem. Also, I don't think it is a transmission issue, since that system wasn't touched in any of my recent repair work. Could a dirty or failed EGR Valve cause this type of issue, or could a leak in my exhaust system be the root cause? I am starting to run out of ideas of things to check, so any suggestions on how to further troubleshoot would be greatly appreciated.

I own a 1995 Lexus ES 300 with 110,000 miles and am located in Northern New Jersey. Recently I replaced all six spark plugs and all six plastic coil connector clips, which is the first time that these items have been replaced on my car. I used NGK OEM Iridium spark plugs from Autozone and OEM connector clips. After finishing the job, the car started OK the first few times but ran extremely rough and would not rev beyond about 3,000 RPM. After successfully starting it 3-4 times, it now will not start up at all. I have rechecked all of my electrical connectors and air hose connections, reset the on-board computer by unpligging the battery, and found no error codes on my OBD II reader. Wouild one bad plug/coil/connecotor set prevent the car from starting up? If so, is there any easy way to diagnose which plug/coil pair is causing my issue? If dirt or grease had accidentally gotten into my air intake manfold or throttle housing, could that be causing my start-up and rough engine issue? Any suggestions on how to further troublseshoot and isolate my exact problem would be greatly appreciated. Thanks in advance for your guidance!

I am a new member to this forum (located in northern New Jersey) and recently acquired a 1995 Lexus ES300 from my Dad. The car is in very good condition and has 105,000 miles on it. I have been experiencing intermittent A/C operation over the last several months. After observing it during this period, the A/C seems to work fine on slightly cooler days and blows extremely cold air, while it does not work at all on hotter days. Also, it appears to change states (from working to non-working condition) between ignition starts. I am seeing a solid green light on my A/C dashboard control unit at all times. Before checking the freon levels, I tried replacing the A/C compressor control relay (which did not fix my problem), since this is a very common problem with mid-90's Lexus models. Also, I ran the Lexus ECU HVAC diagnostics and received only the 00 code, which indicates normal working operation. Next, I measured the A/C system freon pressure levels and found 105 psi on the high side and zero or very little pressure on the low side. Essentially, there is little if any vacuum in my A/C system. I tried adding freon, but the car did not appear to take any more than about a half of a can (if any) freon. Also, when i turn on my A/C unit, the compressor clutch appears to be turning (engaging). After reading through these forums, it appears that my problem may be due to a bad (stuck) expansion valve (a common problem with mid-90's Lexus models), which is consistent with my pressure readings and driving observations over the last several months. However, before proceeding any further, I wanted to solicit other opinions to confirm that my expansion valve is the likely root-cause of my problem. Here are a few questions that I have: (1) Are there any additional tests that I can perform to further isolate my problem and confirm a defective expansion valve? (2) Which front dashboard items (besides the glove box compartment) need to be removed in order to replace the expansion valve? Excluding removing the freon and recharging the system, how much time is involved in actually replacing the expansion valve? (3) Should I also replace the drier (or any other parts), since it connects directly to the expansion valve? (4) Would you recommend genuine parts from Lexus or are 3rd-party aftermarket parts OK for this job? Thanks in advance for your guidance! Any help on how best to change out this part would be greatly appreciated!