sfm4103

Thanks for taking the time to lay out what might be causing the problem. The problem is intermittent. Does that eliminate any of the issues you mentioned? Besides working on the air intake ducts and cleaning the throttle body, if it were your car, what would you repair or replace next? Thanks again Smooth 1.

Not sure what TCS is, but no lights flicker

My 99 GS300 is sluggish when making a turn and with acceleration after slowing down. It's like the engine bogs down, but returns to full power in about 3 to 5 seconds. I get good power accelerating from a standing start. My GS has 120,000 miles. Spark plugs, air filter, and MAF sensor have been replaced recently. ECU has been reset and I've tried it with the VSC off. Other than these problems, the car runs great. I'd appreciate you lettting me know if you have any ideas what might be causing this. It is getting dangerous to drive this car!! Thanks

Looks like Seafoam fixed my hesitation problem. No hesitation in 1.5 weeks. Thanks to everyone that made suggestions and especially to Menappi for his Seafoam suggestion. He saved me a ton of money and aggravation. Thanks. Have you had any hesitation since??? Lexus diagnosed mine with clogged catalytic converters; howver, that didn't fix the problem. So they replaced the wires and the coil packs. This solved the problem. So if you still have the problem this might be a place to look. The symptoms you described were identical to mine, but they are gone now. FINALLY! Hello, I too have been feeling this hesitation in my '02 GS430. I cleaned out my MAF the other day using CRC Mass Air Flow Sensor Cleaner but it didn't help. I'm going to try the Seafoam suggestion to see if that works and if not, I too will probably purchase wires and coil packs. Can you clarify that the wires I need to replace are the spark plug wires and the coil packs (ignition coil?) are what the spark plug wires are attached to? If that does not work, I'll look into replacing the MAF sensor. Where can I buy the wires and coils and MAF sensor for cheap? Thanks again everyone! I finally fixed my problem by replacing the MAF sensor - $ 165 from Hoy Fox Toyota Lexus in Texas. They have great prices on Lexus factory parts. The link is http://www.trademotion.com/partlocator/ind...956&make=20 For some reason the Seafoam would mask the problem for several weeks, but it would gradually come back. The new MAF did the trick and it has been over 2 months without any hesitation.

99 GS 300 AC gets too cold. In auto mode I have to keep the control temp between 80 and 83 degrees to be comfortable with outside temp at approx 90 degrees. The higher temp setting lowers the fan speed, but I think the compressor may be running all the time. I have the same problem in manual mode. Any suggestions on what might be causing this?

Looks like Seafoam fixed my hesitation problem. No hesitation in 1.5 weeks. Thanks to everyone that made suggestions and especially to Menappi for his Seafoam suggestion. He saved me a ton of money and aggravation. Thanks. Have you had any hesitation since??? Lexus diagnosed mine with clogged catalytic converters; howver, that didn't fix the problem. So they replaced the wires and the coil packs. This solved the problem. So if you still have the problem this might be a place to look. The symptoms you described were identical to mine, but they are gone now. FINALLY! Sorry for the delayed response - computer crashed. Glad your problem is finally fixed. After using the SeaFoam, mine ran perfect for approx. 3.5 weeks. Now the hesitation will happen maybe once every 3 days. I notice it more now when I make a turn and accelerate. I'm wondering if I have water in my tank. I'm trying a fuel additive that removes water. If that doesn't work, I'm trying the MAF sensor. I have replaced the wires (no coils) and that did not help. Are coil packs expensive and did they say why they think the coil packs caused the problem? Again, congrats on getting your problem fixed. We'll talk again when we have the next problem. Get ready for a starter. I'm replacing mine on Monday !!!!!! I'm glad I own a GS3 - 2 hour job-starter comes out the bottom. GS4- 6 hour job.

Looks like Seafoam fixed my hesitation problem. No hesitation in 1.5 weeks. Thanks to everyone that made suggestions and especially to Menappi for his Seafoam suggestion. He saved me a ton of money and aggravation. Thanks.

I bought SeaFoam at NAPA for approx. $ 7.50. You can also get it at most Pep Boys and Auto Zones. Add a full can to a full tank of fuel. Check out their website at www.seafoamsales.com. I drove 100 miles today and still no hesitation.

Well, I got so sick of the problem and broke down and took my gs to the dealership for a diagnostics. I should have the source monday. I'll keep everyone posted. After $150 of diagnostics at the lexus dealership, they came up with a clogged catalytic converter. The car was sent to an exhaust specialist and they did temperature readings of the inlet and outlet of the catalytic converter and found that one was clogged. Now, here is the bad news...really bad news, the converters are part of the entire exhaust manifold so in order to replace the converters one would need to replace the whole assembly and an assembly from Lexus is $900 and installation and other parts total up to $1400. On the other hand, you can cut out these converters and weld one in its place. If you took this route, depending on who you went to, would cost roughly $600. There you go. I'll let everyone know if this works. Sorry to hear about the $ you're having to spend, but I guess it will be worth it if it fixes the problem. It's cheaper than trading cars!!!! I'm not a mechanic, but it seems like you would have constant performance problems instead of intermittent it the CC was clogged. Update on my SeaFoam try. I'm now on my third day without SeaFoam in my tank and the hesitation problem has not occurred once and performance is better. The jury is still out, but so far so good. I'll let you know the results in a couple of days.

The SeaFoam seems to be helping with the problem, but I still have some left in the tank. It certainly gave me more power. I'll know more once I put more gas in next week without using the SeaFoam. If the SeaFoam doesn't fix it, I plan to replace the MAF sensor. Thanks

I've ordered the MAF sensor. What is TPS? Thanks for your info. Hope the MAF works.

I took it out a blew it out. Should I try to clean it with a liquid? If cleaning does not work, I'll replace it. Thanks for your help. I have heard you can dip it in rubbing alcohal then let it dry. But to be honest its a pretty cheap part so its probably worth it to just get a new one. Might help with MPG as well as performance. I think they sell refurbish ones, if you buy a refurb just make sure it comes with a warranty. J Have you ever reset the ECU ? TPS ? How do you do that? Disconnect the neg. battery terminal for 10 min. This will clear all the memory stored and the car will relearn driving habits of the driver. Maybe there is something stored in the ECU that is causing this HICKUP................ I reset the ECU last week and cleaned the MAF sensor with alcohol last night. Still have the hesitation problem. I plan to replace the MAF next week after vacation

I took it out a blew it out. Should I try to clean it with a liquid? If cleaning does not work, I'll replace it. Thanks for your help.

I've been told that 99 GS300 has a lifetime fuel filter located in the gas tank located under the back seat. I think I'll replace it anyway and try your Seafoam idea. Thanks for your suggestions. Ok, please do I am in desperate help! Please do and feel free to email me at ashtonparker@hotmail.com. If I have any luck i'll let you know as well. OK. I know how aggravated you must be. I know I am. I'm getting close to the point of getting rid of the car if I can't find the problem soon.

Idle and acceleration are both good. That's why I wonder if the fuel filter is causing the intermittent hesitation.