Check Engine Light After Refueling

[zia]

Hey guys,

I was in the middle of the country when my 99 GS300 ran out of fuel. Then had it taken to the closest station and put 89 octane gas. Ran fine for the whole tank and then filled up with another tank of 89. After driving about 40 miles the Check Engine Light came on. Took it to the dealer, paid 140+ and was told have to change the Catalytic converter AND sesors for $2200+.

Took it to Midas they checked it and said I have bad fuel type in it and should put Premium first and try it out plus he said my car has 2 sensors and he is seeing them "moving". So my question is do you know who I can believe??? And also how do I reset the Check Engine light?(I don't have original keys)

This is truly a tricky question,

Thanx,

Zia

[djspawn00]

What codes triggered your check engine light(CEL). You can take it to an autozone and have the codes pulled for free.

[stroked4.6]

The dealer could have been bull*BLEEP*ting you. I would go to autozone and get the code read yourself. Post what code came up and we could give you more help then.

It could be something as simple as not securing the gas filler cap properly. Putting in a grade lower octane wont screw anything up. I’ve been putting 89 it in my car since I bought it 3 months ago and the previous owner was using regular fuel. I wouldn’t recommend regular fuel but nothing that detrimental will happen unless you go full throttle and really push the engine. Lower octane will cause pre-ignition or detination which you will be able to hear (sort of like a pinging on partial throttle and gets worse with acceleration). Unless your really pushing it you shouldn’t have a problem.

Now if they put diesel fuel in your car that could possibly screw the cat up as well as plugs and some sensors but the car would run like crap and stall out. This actually happened to my sister (long story).

I would trust the Midias guy in this situation. The "moving" sensor voltage are the oxygen sensors which control the a/f ration. The voltage signal is constantly changing.

So i would put some 93 octane in and a fuel injector cleaner. Then get the code checked at autozone and post it online. Hopefully we will able to help.

[92Lex]

What codes were thrown?

[anthonyiez]

the rear (post cat) sensor should not move. it should stay relatively in the center showing the cat actually did its job. if the rear sensor is fluctuating then it is reflecting the cat didn't clean a damn thing.

[zia]

Hey Guys, thank you so much for the help. I will post the codes as soon as I go back and get them. Thanx

[zia]

Hey guys, the mechanic said the sensor is p0420. Also, this is strange, while driving back, the car stoped running, it was starting then turns off. Gas still 1/4 left.

I called a toe truck & took it back to the mechanic again after around 45 min but this situation didn't happen again in his shop. Did my engine get too hot or something. Please any word on the 2 topics would be very helpful. Thanx

[djspawn00]

Hey guys, the mechanic said the sensor is p0420. Also, this is strange, while driving back, the car stoped running, it was starting then turns off. Gas still 1/4 left.

I called a toe truck & took it back to the mechanic again after around 45 min but this situation didn't happen again in his shop. Did my engine get too hot or something. Please any word on the 2 topics would be very helpful. Thanx

Did the temp gauge show the car was overheating? As far as the code goes P0420 "Catalyst System Efficiency Below Threshold Bank 1" Didn't accidently add diesel ever did you? It could be the exhaust flanges (connect cat's to mid-pipe)directly after the cat slightly corrode from rust.. exhaust leaks out causing a false wave pattern read by the rear o2 sensors making the ecu think that the cats are not working.. or it could be a faulty sensor... or an actual bad cat. Have the CEL light reset at autozone or the shop that pulled the code and see if it comes back on. Other than that I have no idea why your car cut off.

http://www.obd-codes.com/trouble_codes/gen...hold-bank-1.php

[zia]

Hey djspawn00,

Thanx a lot for the tip. I have done wat u said and put in premium gas and had the Check engine light reset. So far it didn't come on yet. BTW, the driving was done while the gear was in 4 not in D so mayb that could've shut it off.

Really appreciate it bro, I just hope the Cat is not messed up as the dealer told me earlier $2200+ to fix it. I wish there were a parts store if I really needed it in case.

Thanx,

Zia

[djspawn00]

Hey djspawn00,

Thanx a lot for the tip. I have done wat u said and put in premium gas and had the Check engine light reset. So far it didn't come on yet. BTW, the driving was done while the gear was in 4 not in D so mayb that could've shut it off.

Really appreciate it bro, I just hope the Cat is not messed up as the dealer told me earlier $2200+ to fix it. I wish there were a parts store if I really needed it in case.

Thanx,

Zia

Hopefully the cat is not messed up, but if it is you don't have to spend $2200 to fix it. You can get an aftermarket Cat and have a reputable muffler shop or indy slap it on for you. If you want an OEM part you can probably order it from irontoad.com or another lexus parts site.

unusually cheap but heres an example of a part, may not be exact so don't buy this one without checking...

http://cgi.ebay.com/ebaymotors/Lexus-GS300...sspagenameZWD1V