I'm having these two issues and I feel like they might be related.

Check engine came on for the first time yesterday and I pulled code 25 today. Also had the trac light come on simultaneously.

When the engine is being started for the first time it is extremely hard and takes a few minutes of cranking to start. It's like it's not firing on all cylinders and once it does start running it misfires until it clears out and then runs perfectly smooth for the duration of driving.

While cranking it seems like a spark issue over fuel as it smells of carbon and unburnt fuel


Idle is perfect at 900 in neutral, about 5-600 in gear, which should be normal. Doesn't hiccup, misfire, or anything when driving. It's smooth as can be.

Any predictions as to what the problem is? I'm going to start going over things one by one but someone may have a better idea of what to check first.


thanks,
Matt

 

honestly it could be anything, theres so much that can go wrong with these cars, i would start by doing a tune up. how long have u had the car, has it ever had issues before? piks?

 

https://www.clublexus.com/forums/mai...c400-auto.html

https://www.clublexus.com/forums/sc-...lfunction.html

https://www.clublexus.com/forums/per...-od-light.html

https://www.clublexus.com/forums/per...xxx-miles.html

https://www.clublexus.com/forums/per...code-25-a.html

All ya gotta do is SEARCH!

Based on these threads, the majority points to the upstream o2 sensors. Replace them, no hard start, no guzzling gas, no nothing.

GL.

 

I searched through google and I literally got only one of those threads. But thanks! lol. I figured it was o2 sensors. Thinking it's lean and overcompensating and dumping fuel

 

Oh and I've had the car four days. lol. Going to do plugs tomorrow and see what they tell me and then probably try some new o2s. Can't hurt even if it isn't the problem.

The car has been significantly easier to start today.

Matt

 

Do the o2s! I just had code 25 even after buying aftermarket ones, then installed my old oems and it went away. Couldn't believe a new bosch sensor would give me a cel compared to an old o2 but im happy now lol.

 

Might want to try the coolant temp sensor although the code points to o2.

 

^Do this too. Cheap and super easy to do. Google ECT sc400 or ls400 lots of guys have had good results.

 

I Have The Same Code And Have Noticed A Slight Drop in my radiator coolant level yet there i go and check my oil and its clean no sign of coolant. And i have all new coolant hoses and brand new thermostat

I Changed my ecu because my car wasnt going into 4th gear. The ecu solved that problem but now code 25 and same exact idle problems

 

The code comes on and off intermittently but is more frequently off. Also the car started starting normally. I'm going to bank on bad gas, the car was sitting since the spring

 

Might want to replace the o2 sensor to see if it fixes the problem.

 

Well you could have mentioned that before hand...

If bad gas is what you think, go ahead and pump the gasoline out of the tank, /and/or run a couple of injector cleaners through the system.