New intake hose, now rough idle with a CEL on...

[PortugalFocus]

Well, I went to change my accordion style air cleaner tube and resonator with a modified aftermarket one. Well I did so. I removed the assembly and swapped it out with an aluminum tube with 2, 3" Spectre silicone couplers at either end. The install went pretty smooth, I got it all back together. I let the car idle for 10 minutes to check for leaks, none found. I went later this evening to drive the car and it has a lumpy idle now. The CEL popped on. It will run very well under full throttle, and in the midrange, it's just at low rpms that it doesn't idle well. It will move if I want it to, I just don't want it to act this way, plus it also signs horrid when sitting still.

I decided to disconnect the battery and let it sit for a bit to see if the ECU needs to reset and maybe learn the new airflow. I will clean the MAF in the AM.

I was just wondering if anyone had come across this before.

I have a 00 with the 1MZ w/ a 5-speed.

All hoses are connected, checked and double checked.

Thanks

[PortugalFocus]

I got the codes checked and I have P300 - Random Misfire and P401 - Excessive EGR Flow.

I'm not sure if it's random or intake related, but it may be.

I will check the EGR valve, plugs and wires.

[toyomoho]

Guessing the new intake pipe has air flow problems that are causing the MAF sensor problems.

Reinstall the old unit and determine if the problems go away.

Did not think a 2000 computer had any learning ability to adapt these part changes.

[bigbird]

hmmm....im having this same problem. when i took my S/C off and replaced it with jsut a short ram it had a really rough idle and the same symptoms, low rough idle and egr excessive, but fine above 2500 RPMs. i thought it was the EGR valve and it wasnt dirty and replacing it did nothing. so the egr VSV seems to be the culprit. BUT...

if this happened after you changed the intake maby thats the problem. have you tried replacing the stock setup? id do it to rule that out, other then that its most likely the VSV or EGR valve itself.

this is on my 97 V6

[PortugalFocus]

yes, I swapped back to the OE accordion tube and still the same symptoms.

I will check the EGR valve and clean it out. My car has a boatload of miles, almost 240k.

I checked all plugs and wires. They are tight and secure. I also checked the ignitor for signs of corrosion and water, nothing found there.

[PortugalFocus]

Well, I did some work yesterday:

New timing belt
New Water pump
New Tensioners
New NGK Platinum Plugs

With all this the car runs like a new car, and had much more of the lost power.


I found the issue with the car that I had as I listed in the first post. The problem was a clogged EGR valve. I tried cleaning it and cleaning the sensor, but I think there's something wrong with the diaphragm. A new one is around $170+, ouch. I have the vacuum disconnected from it and it's running great for now. I dunno if a CEL will come back on or not. I don't think I want to try and source a used one. So if anyone has a new one for sale, let me know.

[slpr1mz]

take out the egr position sensor, and check it. if you deprese the stem and feel any resistance, then its probably bad. thats what happened to me... luckily i got a code reader that told me more than what toyota and other shop readers where telling me....
the stem should glid with almost no resistance, well lubed feeling...
also take out the efi fuse, keep your battery installed.
about 20 min put it back in and run your car hard for about 5-10min...
the ecu can adjust it self, i did it on my car and i'm gettin better gas mileage
as well more mid range pull...