Brownd3max

Wife & I loaded up our recently acquired '98 es300 for a 3 hour trip to Phoenix airport for a flight to LAX to catch a Cruiseship. I had just done all the preventative fluids/ plugs/ filters- everything I could think of... Then, just after leaving the house, only 5 miles away, it started to "hiccup" on the road. 'Check Engine' light came on solid. Momentary "pauses" in power, a reduced power feeling, varying in longevity and duration. Crap! Had to quickly turn around, run back home, reload the other car, and start over! The only good thing is this didn't happen 100 miles from home! Now what? Do I buy an OBD reader? Any help would be appreciated!

LeX2K

You need to check for any codes using an OBD-II reader. Even the most basic one will work.

Oro

Brownd3max

UPDATE- today I had the OBD read, and these 3 codes are on steady with periodic flashing, then back to steady on: P300, P3032, P303. Now, I take this as cyl.#2 and cyl.#3 sporadically misfiring. If cyl.#2 is Front Left, and cyl.#3 is Center Rear, why would these TWO start acting up at the same time? Big Coincidence? Or?

LeX2K

Could be bad/clogged oil control valves and clogged screens do a search on this forum for the bolded. Some people have not had good luck with aftermarket others say they work fine I would buy OEM.

https://www.clublexus.com/forums/es-...ing-codes.html

Oro

My first instinct was also OCVs. I can’t perfectly correlate that to the codes reported. There’s nothing inherently common to the two banks WRT to the OCVs. I think the oil feed lines are separate. There are screens at the head end of the feed line you can remove and inspect as a sudden debris accumulation there could affect both; some crud elsewhere cut loose, though unlikely (would have to get past filter as the feed oil to the ocv’s is just after the filter I believe.

DJPsystems

98 does not have VVTI so there is no oil control valves. Could be something with the ignition system.

Brownd3max

Whoa- WTH?!? I'm now officially confused. You're the first one to point this out.

LeX2K

Disregard what I said about the OCV's I got this car mixed up with another one. Does your car have 3 coil packs or 6? I believe it has 3 which means a bad coil will cause a misfire on 2 cylinders because the coil is responsible for firing two spark plugs. Swap the front coils around see if the problem moves. If not check the injector connectors for cracking or not being plugged in properly. I've seen the pins get corroded and cause a random misfire cleaning them fixed the problem.

Brownd3max

Now that it's been established there's no OCV's on this '98 V6, (engine cover "confirms" this), this is where I'm at- I've replaced the plugs, the 3 plug wires going to the rear bank (w/oem), cleaned the plug-in connectors to the coils. Still have the rough-running misfire. I checked the coil resistance at the connectors, and saw about .8 ohms on all three. Not sure how to measure the other side of these 3 coils, if even possible? I plan to unplug the injector connectors and spray-clean them, as suggested by Lexus2000. I'm leaning towards coil replacement at this point, but don't want to spend the $ if not needed. Are there any other connections/ sensors I can spray/clean that might be involved in this sudden onset mis-fire? Thanks to all that has chimed in so far!

Htony

20 year old ES! If you have newer vehicle wouldn't that be first choice? I never own cars more than 5 years. Wife insists on driving a car for 10 years. She does not drive much. Just run about around town. After 10 years it does not even log 100K miles.

Oro

Brownd3max

"...First choice"? Well, since you asked- IMO, a 20y.o.Toyota/Lexus w/124K miles should be a safe choice for a 3 hour roadtrip to the airport. That's why I bought it. As I had just got the car a few weeks prior, I thought doing the usual fluid/filter/plugs R&R would've sufficed. Another reason for my choice was my other car, a BMW M3 with a pristine body/paint would have been at the mercy of Valet parking attendants for 2 weeks parked outside at the Airport. LOL!

Brownd3max

Well, well, well- don't I feel like an idiot?!? I decided to look further at the injectors, after "Lexus2000"s reply on my other related post. After removing, cleaning, and reseating all the easy injector connector plugs, I came to the rear middle one, hidden under the intake plenum. Upon (painfully) squeezing my hand under the intake, I felt the connector was loose! Just sitting on it's mating connector! Eureka! Snapped it down with my fingertips, and "Oh, happy day!" (Redd Foxx quote)LOL! Runs great, and no codes thrown after a fast 'n furious roadtest.

LeX2K

Thanks for the update. You case is about the 4th or 5th I've seen where an injector plug was either dirty or not plugged in properly. When misfire codes show up people think spark spark spark hardly ever injectors even though they can cause the same codes.