95ARISTO

Hey guys, my situation is exactly like what the title states. When cruising on the highway, at exactly 55mph my car bogs and hesitates. If i let off the gas a little bit and then slowly engage again until past 55mph, the car runs smooth again. However, if when bogging and hesitating at 55mph and i depress the pedal more, the car will not pick up speed at all. This is what initially happened and now at lower speeds the car hesitates too. There is also this feeling of hesitation before engaging when i step on the pedal to go at a stoplight. What could be my problem guys? I've drained out 2qts of tranny fluid and filled with new stuff and still no help. Actually, I think after i did this, the slipping to engage at a complete stop started. I used Toyota TIV but on my dip stick it says Type II. Any difference? The guy at Lexus said that it should be fine. I spoke to my uncle who's a mechanic and he said that it could possible be a solenoid/sensor in the transmission control the overdrive. He said that if at 55mph I turn the OD off and the hesitation goes away, then the solenoid/sensor is bad. If it doesn't go away, then the tranny is no good. What else do you guys think could be my problem? This has been buggin me for the past 2 months. Any advice would be appreciated.

Here's a more organize outline of my problems and things if done in attempt to fix it:

Problems:
1. When stepping on gas at a complete stop, car shutters and hesitates before jumping into gear.
2. When giving it more gas, car hesitates to completely engage and run smoothly across the entire rpm band. It sometimes will stay at a particular rpm and then drop and then go back up... and so on.
3. At exactly 55mph, the car bogs and will not go any faster even after i press on the gas.
4. WIth the transmission in park, if I turn on the A/C, the engine shakes every now and then as if it were misfiring.
5. Sometimes after driving a long distance and i park the car, I can smell something similar to the smell of a burnt clutch. Like the smell on a manual transmission when you drop the clutch a few times to do a burn-out.

Fix:
1. Oil change
2. tranny drain and fill
3. clean throttle body

I apologize for this being such a long thread, but my head is about to explode trying to figure out this problem.

95ARISTO

Any ideas???

Kaiser

iTrader: (1)

O2 sensor. My car had a similar issue. If your trans was slipping than the rpms would go up but you would go nowhwere.

95ARISTO

Would an O2 sensor have that big of any effect on engine performance to the point of bogging? Also, if my O2 sensor was bad, wouldn't my CEL come on?

Kaiser

iTrader: (1)

Yes the O2 sensor can definatley make the car bog. It is what determines how much fuel is going into the engine. You would think that it would throw a code but mine never did. I cleaned my grounds up and the stutter improved, I changed the O2 and it went away. It felt like I was dragging an anchor until I passed 3800 rpms when the car went open loop and ignores the O2 sensor.

Does it bog like this when the car is cold?

link13

Are you getting a check engine light at all? Even if you didn't see the light, there's probably an error code stored in the ECU. Try pulling the code to diagnose your problem.

95ARISTO

That's exactly how mine feels...like it's pulling an anchor until it reaches higher rpm or above 55-60mph. When the car is cold, there isn't much bogging as oppose to when it's hot. When cold it feels like the car has more power. I think it was you who I bought the MAF from...right? When I had that situation with the MAF going out after I cleaned it (DAMN CRC), my car didn't run correctly when i took it for a spin and died on the road. AFter numerous attempts to start it up, I finally got it going and made it safely back home. However, when I did get it going, the car ran like S$#% (felt like my situation now, but ten times worse) but i pushed it anyways to get home. Could this have caused my current problem? As for grounding, i'll have to search for you previous thread about it.

Link13: Yes, i do have a code. There's only one actually. Code 17, Camshaft Position sensor. The wierd thing is that it comes on and off ramdomly. It doesn't stay on all the time.

By the way, thanks for taking the time to help me out here guys...I really appreciate it.

Kaiser

iTrader: (1)

I have a set of O2's in my garage I think that you can have. I don't have any use for them as I have a JDM now.

How many miles per gallon are you getting? When I switched out my O2 I went from 17 to 20.

Try reseting your ECU to see if that helps. It's a 30 amp fuse in the box under the hood called EFI 1

95ARISTO

That would be sweet if I could have those o2's. I was just looking at prices for them and it would cost me a leg and an arm for new ones. Do you have all three of them? Before all this trouble, i normally get around 20-22mpg with conservative driving. Now I'm even lucky to get 17. I'll try reseting my ECU too and let you know what happens.

Kaiser

iTrader: (1)

It's the O2 sensors before the cat that make any difference at all and I'm pretty sure I have both of them. I still need to look.

95ARISTO

Alright, I tried resetting the ECU but it didn't seem to help much. However, when near 55mph, i turned the OD off and the hesitation that normally occurs at that speed went away. The bogging at lower speed is still there though I guess the sensors are what i have to try next.

link13

All the ECU reset does is temporarilty clear the error code. If you have an underlying problem, it will resurface. I have not had the o2 sensor problem thus far, but I need new cats. No bog or error codes, but the front cat leaks and it sounds like crap. I'll try to get ahold of my mechanic and ask him about the error code you posted and what causes that. You could also call a local Lexus dealer and they should be able to help you over the phone.

95ARISTO

Sounds good, let me know what your mechanic says. I'll call lexus too and figure out what it is and what it means.