DnJ90

About 2 months ago I had the CEL come on on my 98 GS 400.The code was the 420 code.Dealer changed out the oxygen sensor no worries for about a month.Than CEL comes on again for about a day then goes off.Now about a month later it does the same thing.Went on for a day and is now off.Any idea what would do this?Could this be a bigger problem?

offbad

iTrader: (5)

are you sure your battery is in good condition?

Mr Jokster

iTrader: (8)

It could possibly be one of the catalytic converters

angus

iTrader: (4)

Yup, cat is going bad.

KeyKeeper

If your not running prem fuel, then start doing so.

DnJ90

I hope not

DnJ90

I've been running Premium in it since I got it in August.Don't know what was run before that.

ttaylor993

Are the codes the same? It could be a totally different issue(s).

DnJ90

I'll have to check next time it comes on.It went off before I could take it to get it read.

lexo98

iTrader: (2)

$10-$20 on ebay for a blue tooth or wi-fi OBD2 reader and a $10 iphone/android app and you can read and clear codes yourself.

ttaylor993

It doesn't matter if the CEL is on now or not. If it came on at all, then the car dropped codes into memory and you should be able to get them with a code reader. The codes will not be erased except with a code reader or in some cases when the condition has been corrected. The fact that the light comes on and off would lead me to believe that a condition still exist.

poloSTL

i go thru this crap every year. i am having issues with monitors not completing= Fail

plan to get OBD2 reader for next time and what is name of android app??

thanks,

Polo

lexo98

iTrader: (2)

I hear the app Torque is great but it's not available on iPhone apps. I used OBD2 Fusion. It showed the MONITOR REDINESS. If you disconnect your battery to clear the check engine light before smog you need to drive through a series of patterns that check the vehicles sensors. The app will tell you when they are complete and here is the way to get it in readiness mode. http://www.ih8mud.com/tech/tsb/LexusLX450/eg002l02.pdf

ThomasGS4

iTrader: (19)

Exhaust leaks post-cat and pre-downstream O2 sensor will push that code as well. Check the inexpensive stuff first.

poloSTL

Thanks buddy. I know i have bad O2 heater sensor but cannot afford to replace at this moment.
MY problem again is not being able to complete both catalyst and evap monitors after reset check engine light. Usually light comes back on after 2 drive cycles... SO FRUSTRATING

I plan to purchase this for $6.59 at Banggood.com
ELM327 V1.5 Bluetooth OBD2 II Car Auto Diagnostic Scanner

Unfortunately gonna take 7-20 biz days to receive

Thomas, u have any tips for drive cycle??



Polo