gibygreen

Hey there everyone! Just picked up my first IS300 today for the low price of $2000. It's a 2001 automatic in pearl white, with 229k miles. Aside from mileage the car exterior wise and under the hood is in really great condition. The engine bay is the cleanest part of the car. Overall it runs and drives relatively well and made the hour long drive home.

The only problem i'm having with the car is a sort of hesitation. In every gear, the car runs great until 4k rpm, it stutters and essentially refuses to rev any more than 4,200 until shifted. And in (4th? I think.) it will not automatically shift up from 4k until letting off the pedal. The car has one check engine code for P0161, which is 02 sensor 2, bank 2. I cleared the code and it hasn't returned but the car still runs the same. Also, it tends to bog a little when given throttle too quickly in and out of gear and pings slightly. Under normal driving the car runs pretty well, so what's up? Is the 02 sensor at fault here?

I plan on running all the service on the car since I got it from a used auction, it hasnt been done in a long time. I don't know much about toyotas so i'm a bit of a loss here. Thanks!

(Also, should I be worried about the transmission at this kind of mileage? it seems to do fine until the 4k shift.)

01MSMSXE10

Couple of questions to better narrow this down. What RPM does it idle? This sounds crazy, but when the valve covers leak, oil gets between the camshafts in the spark plug galley. My plugs were soaked in oil, and my vc gaskets had rigormortis.

Have you checked voltage from your APPS on the throttle body? (it could be starting to fail) this will cause a hesitation in throttle response, or it could be simple as a broken connector or a loose wire. check that first.

When was the last time the timing belt was changed? Did you do the service? I've seen some people on the FB page post that their reluctor wheel had broken teeth preventing the engine from revving past 3500-4k


I just had to replace mine, it was causing a p1120 code. I was half tempted to set the damn thing on fire, but then remembered it's my only car with AC

gibygreen

Hey thanks for the response. I actually managed to fix the car myself. New plugs, can of seafoam and a new MAF sensor (Denso maf) and I've got it running great, like a completely different vehicle. Still getting 02 sensor 2 bank 2 p0161, but thats just for heater circuit and the car runs normal.

uttim22

I did the same thing gibygreen did minus the new plugs on my '02 that was running rough and triggering the CEL. The codes were for a misfire and supposedly a bad O2 sensor (Bank 2, Sensor 2). I pulled the MAF sensor and cleaned with some electronic cleaner (NOT MAF SENSOR CLEANER) the dealership repair manager recommended. The red diode on the sensor was so dirty it looked black. Reinstalled and ran a can of Seafoam injector cleaner through the gas tank. I also bought a basic code reader to check any future problems. After I reconnected the battery and ran the car through a normal drive cycle the CEL light went off and hasn't gone back on since. No error codes anymore. Total repair time was around 15 minutes. I'm glad I took this approach instead of jumping to replacing the O2 sensor. Total repair cost ended up around $45 ($25 code reader, $12 can of Seafoam, $8 can of CRC Electronics Cleaner). O2 sensor repair would've been over $500. Car runs like new now. No acceleration lag, gas mileage is up a bit and the car itself feels a lot more peppy. I highly recommend everyone that owns an IS clean their MAF sensor every year to year and a half for greater longevity out of their vehicles. It's part of my yearly maintenance routine now!