trhs75

Also think about buying a code reader -- I got one at Costco for $30 or $40 --just used it this week for the first time. Well worth the money!

AlexusAnja

Did you tell them that you just got the plugs replaced a few days ago? I presume that they were not replaced at a Lexus dealer or they would know on the computer history check. So, are the plugs then totally wrong (type), installed incorrectly, or gapped incorrectly? If the plugs are correct, but just gapped/installed wrong, then the dealer should just use the existing plugs.

$500 for six plugs is kind of steep. I had mine done at Lexus for $220 installed and got a nice loaner for a day. Try to talk that price down, you're talking almost $100/plug, that's crazy.

As for Autozone, yes, they will read all your codes for free. They might just give you a code, so you'll have to search online to see what each code means.

salimshah

When I replaced spark plugs, immediately one of the coil packs went out .. misfire went from one cylinder to another cylinder.

Salim

99Lexusrx

First, thank you, everyone for the advice.

I was having problems with my transmission not shifting into O/D.

I took the advice to disconnect the battery and pull the ECU fuse. I did this and waited for 1hr to reconnect everything. I drove the car and after about 2mi. the CEL came on again. Althought the CEL came on, the transmission shifted beautifully into overdrive. This was great. I was still a little concerned about the CEL and wondered what the code was. So I took somemore advice and went to Autozone today and had the code checked.

The code was P0125 (Insufficient coolant temperature for closed loop fuel control). A bad ECT (Electronic coolant temperature sensor). The part cost $24.00 @ Autozone. Looks like I have a little work to do this weekend.

Thanks everyone for the help.

ch53

99LexusRX - what was the outcome of the ECT sensor replacement? I am faced with the same issue.

99Lexusrx

CH53...The CTS part costs $24.50 @ autozone. I haven't changed the part out yet but the change looks straight forward. I did buy a Haynes manaul for the Toyota Highlander/lexus RX300/330 that Autozone sells. The replacement directions are striaght forward and shouldn't take too long. Apparently , you need to drain the coolant so it's below the CTS level, remove the CTS with an open end wrench. apply teflon tape to the new CTS part and install. Just thread it back in. The Haynes manual gives you location directions and pictures. I'm probably going to change it out this weekend.

It's not that I'm not worried about the consequences by not changing it right away, but the only real issues are some fuel idle hesitation below 1000rpm. or possible fuel loading in the Catalytic converter. I don't let it idle too much so it doesn't seem like it would be an issue until the weekend. I'll let you know

99Lexusrx

Update...The CTS was harder to find than it was to install. It is located on the coolant return housing on the left side of the engine (looking from the front of the car) near the end of the return hose. Disconnected the battery terminals, drained the coolant/anti-freeze, disconnected the wiring plug, removed the CTS with a deep 19mm socket. Put teflon tape on the new CTS, reinstalled the CTS, connected the plug and filled the radiator. All done within 1hr. Damn check engine light is still on!!!!!!!!

The CEL code only showed 2 possible problems 1) bad t-stat or 2) Bad CTS. I figured the engine was not over heating and was providing heat, so I eliminated the t-stat.

I phoned a mechanic friend and he said that it's possible the t-stat could be stuck half open which would still give me heat and not over heat the engine.

Looks like I'm changing out the t-stat this weekend.

Still no problems with the Transmission shifting since I originally cleared the CEL.

Will keep you updated.

Cwall

The coil pack mixed with wrong spark plugs was the culprit to my problems. I'm getting the car back from Corpus Christi, Tx tomorrow!

ch53

99Lexusrx...I also changed out the ECT sensor, but did not drain the coolant. Removed radiator cap to relieve the pressure, placed a couple of shop towels around the area of the sensor, prepared the new sensor with new crush washer (no teflon tape) and placed my finger over the hole when the swap occurred. Torqued to 168 inch lbs. Coolant loss was negligable, however it did not fix the issue and PO125 came back along with pending P1135 and P1155 (I have an Actron OB II reader). Took the next step, which is the thermostat, even though the warm up time and temp reading appeared normal at two tick marks above C. Drained coolant, removed and performed functional check of thermostat by immersing in water and gradually heating to check for valve opening temperature of 176-183*F and checking valve lift of .394 inch or more at 203*F. Thermostat functioned as advertised. However, with 154,000 miles I decided to replace with a new one from Toyota. Reinstalled with new gasket and torqued nuts to 69 inch lbs. Still had the same codes. I decided to investigate the pending P1135 and P1155 (AF sensors). Took my multimeter and checked the resistance between terminals +B and HT (read somewhere they are the black wires). Resistance should measure between 0.8 - 1.4 Ohms at 68*F. Bank 1 Sensor 1 (aft manifold) measured at 1.2 and Bank 2 Sensor 1 (fwd manifold) measured at 13.0 then after a minute or so went to 0.0. Ordered new Denso from Toyota p/n 89467-48011, sprayed the old one with Liquid Wrench, allowed to penetrate for about 3 hours, removed and installed new one (already had copper anti-sieze on threads) and torqued to 31 ft. lbs. Cleared the codes and all is well. I decided to take a look at some other items as it is my wife's vehicle and I rarely drive it. Removed # 1 and # 2 throttle bodies, throughly cleaned and reinstalled with new gasket. However, I did not replace either o-ring / packing for the internal coolant passage as they looked fine. Replaced spark plugs and torqued to 13 ft lbs (used 1/4 inch drive torque wrench). I did not remove # 3 throttle body to gain access. Replaced PCV valve and grommet and air filter. 1,000 miles after performing the above the average gas mileage has increased 2.9 mpg (from 19.3 to 22.2) combination of city and highway. On the highway the average speed is 73 mph at 2,800 rpm. The above maintenance was performed utilizing the Lexus repair manuals and reviewing the DIYs on this forum, which were very helpful. My thanks to Lexmex, Sticky and others for their postings