apatrules

My GS 400 has 180,000 miles and I started getting occasional Check Engine warning lights after the plugs were replaced at 120,000 miles. Had the problem on and off for about a year and half and then it went away and came back about three years later. All times it was I believe 430 indicating that one of the catalytic converters was bad. I have never believed this reading. Every time I went to the dealer to get the warning light shut off, the light did not come back on for a month, sometimes six months etc. If the cat was bad, it would be back on almost immediatly. I live in Maine where there is no emission check so on two occasions I went back to Virginia and had an emissions check done on the car. In both cases, the emissions check came back without any problem. Last time I had this done (about two months ago,) three hours after the emission check came back as PASS, the check engine light came back on. It was after I had driven in stop and go traffic for about two hours on a hot day. Emission check was still PASS and dealer had no explanation. I believe a plug occasionally misfires and causes something to trip the sensor and falsely indicate that the Cat is damaged. Before going out to spend many hundreds on a new cat, get an engine emission check and make sure the cat is really bad.

Thanks, your assistance has been very helpful.

Platinum edition Lexus (2000 models) used Black Pearl for the trunk Hardware -- Lexus Logo, Model Number and Lexus name. I Needto replace originals because of body work and was told that the Black Pearl hardware is no longer available. Told it is discontinued. Any idea where I can obtain black pearl hardware that is OEM. Thanks.

Thanks. That is a helpful suggestion I will try. Do you know if the light has to remain on for the computer to give a read out of the problem? Also wonder why the oxygen sensor would be an issue when the car is driven in heavy rain. Will check it out. Thanks again. O2 sensor problems, even minor ones can have the weirdest effects on an engine. Always put in an OEM O2 sensor. Just about anything else on a Japanese car can be aftermarket. I've learned the hard way that OEM O2 filter is always the way to go. Thanks. Will get it checked next week andlet you know the results. Brought the car to the dealer who says the computer readout is PO 430--Low Catalytic Converter Efficiency. Of course, suggests replacing Cat Converter for $1500. My unanswered question: If the efficiency of the cat conveter is low, why is it low and light comes on only in certain circumstances--ie heavy rain? And then when the rain ends and car is driven the light goes out. Two questions: 1. How could rain negatively impact the catalytic converters and is there anything that can be done to alleviate this issue without replacing the cats? 2. As earlier indicated, the check engine light never came on in first 120,000 miles of driving. At 120,000 I reluctantly had the spark plugs replaced for the first time (as recommended by the book). And now I have gotten this check engine reading twice in heavy rain. Any chance there is a relation between new plugs and how they were installed and the check engine light? Thanks.

Thanks. That is a helpful suggestion I will try. Do you know if the light has to remain on for the computer to give a read out of the problem? Also wonder why the oxygen sensor would be an issue when the car is driven in heavy rain. Will check it out. Thanks again. O2 sensor problems, even minor ones can have the weirdest effects on an engine. Always put in an OEM O2 sensor. Just about anything else on a Japanese car can be aftermarket. I've learned the hard way that OEM O2 filter is always the way to go. Thanks. Will get it checked next week andlet you know the results.

Thanks. That is a helpful suggestion I will try. Do you know if the light has to remain on for the computer to give a read out of the problem? Also wonder why the oxygen sensor would be an issue when the car is driven in heavy rain. Will check it out. Thanks again.

In more than 8 years owning the 2000 GS 400, the "Check Engine" light never appeared. In September, while driving through a severe rain storm, the light came on. The next morning when I started the car, the light was still on. I checked the gas cap and it was on tight. Drove the care nearly 300 miles and when I stopped the engine and re-started the light was no longer on. The dealer said the engine computer did not record anything related to the check engine light and since the light was no longer on, they could not tell me what might have gone wrong. No problems for two months and then it happened again in the same place (New Jersey) and this time, the light went out when I shut the car off after driving the next day in the dry weather for 175 miles. No performance degradation when the light is on. Any thoughts on why the light would go on in heavy rain. Note: I did not drive through any large puddles that would have flooded the engine compartment. Thanks, in advance, for any ideas.

I have some small nicks and dents on two doors and was looking for a top quality body repair shop in Maine. If no one knows of a really good place in Maine, I am open to traveling to New Hampshire or Massachusetts. Thanks

You must have the GPriuS400! :D HAHAHA GPriuS400.....i could put this on a straight drop and still not get 29 mpg! um im a semi fat !Removed!.........jk im a big guy and i cant live without a/c! plus cracking window hurts mpg ALSO! i dont know anyone w ho has seen 29+ mpg but you! im getting 14-17 in the city depending on how i drive it and 20-23 on highway brian Hey, I was pretty surprised with 28+ mileage on the road and even checked the odometer against the highway mileage markers to make sure of accuracy. Driving around the city in stop and go, I usually would get 19.8-20.4 but did not check all that often. Always have burned 93 octane and change the Mobil 1 every 3,000 miles which is probably ridiculous, but I keep cars a long time. Anyway, the car may be a freak but with mileage consistently like this, that is one of the main reasons that I may just skip changing the Iridium plugs. ap

Have gotten 28 or 29 mph on several trips of 220-250 miles while cruising at 70-72. Once filled up the tank and drove 60 miles on the NJ Turnpike and then refilled and got 30 mpg all the while averaging about 68-70 mph. I don't drive hard and rarely use a/c though open sun roof and driver window cancel out that saving. Just recently, got 27 mpg on 350 mile trip averaging about 75 mph. Another reason I am reluctant to replace the Iridium spark plugs which are claimed to last many times more than platinums. All of the comments have been very useful and I thank all of you including the coasting downhill guy who, at least, gave me a laugh. ap

thank you; very helpful info. ap

Thanks for the recommendation. ap

Approaching 120,000 on 2000 GS 400. Running original spark plugs and have had no problems with misfires or poor acceleration. Highway mileage can sometimes approach 29 mpg. Question is whether I need to replace the plugs. The book says the iridium plugs should be replaced at 120,000 but it also seems to suggest that has to do with emissions issues and not performance. Any thoughts on not replacing the plugs now. thanks

With a GS 400, I get about 19.8 in city driving and have gotten as much as 29 on the open road (something that is non-existent in LA). Also GS 400 mandates premium fuel.

Have had Bridgestone LS-V Tires for about 42,000 miles. Pretty quiet and handle quite well in wet weather. Plus they look like they could last another 20,000 miles or more. But remember, these are the 16 inch rims.