throttle body / fuel injector - 2000 Echo

[mek42]

I recently (~6 weeks ago) had my throttle body cleaned while I had my alternator and battery replaced (we're looking for a third vehicle so that we can have one off the road waiting for parts in the future) and after these services the Echo ran very rough. We complained before leaving the parking lot and were told that the roughness was normal due to the computer resetting from the battery change.

About 3 weeks ago we started having power loss issues. The end result is that last night I put some Chevron Techron in and drove the Echo a bit and significant improvement seems to have been made. (FWIW a Seafoam gas tank treatment last week did not help the problem - I am now a Tachron believer.)

For future reference, I am trying to understand what happened. Could dirt / carbon crud from the throttle body have migrated into the fuel injectors causing a clog?

As far as codes, there has been an ongoing P0171 lean and 440, 441 and 446 EVAP codes that my dealership say is due to the charcoal cannister - I was planning to save up and replace that this summer. (Unless the issue is just the gas overfill valve - we also have issues putting gas in the vehicle - and the OVRV is a seperately replaceable part as opposed to the entire charcoal cannister.) After getting the vehicle back from the initial throttle body cleaning service, there has also been a P0420 catalytic converter code and a oxygen sensor heating element code (I forget the P number and bank for this). Could the oxygen sensor failure be giving the 420? Would taking it in for an exhaust analysis indicate whether the cat is bad?

The Echo currently has 235K miles and I'm trying to figure out whether it is time to give up the ghost or not.

[kathyricks]

The proper way to clean the throttle body is using a toothbrush, a clean link free rag like a microfiber towel and MINIMAL amounts of throttle body cleaner applied to the toothbrush and towel. Only the throttle plate and it's surrounding bore need to be cleaned. Use the towel to wipe up the goo loosened by the toothbrush

Sounds like your engine was drowned in cleaner and the insult was added to injury by your use of gas additives like Seafoam and Techron. Toyotas don't need gas additives.

If you are letting an independent shop that doesn't specialize in Toyotas service your car then they are not qualified to work on your car and their incompetence could be causing all your expensive-to-fix codes.

[mek42]

Well, the problem of rough running / power loss came back. My lesson learned is that the proper way to clean the throttle body is to not clean it unless it stops working correctly.

I have already tried cleaning the MAF sensor with MAF cleaner and no physical contact, air drying like one should.

My wife says that she tried putting in 93 octane gas this morning and there has been some improvement. This makes me think that the engine might be running a bit hot. Doing an oil change and checking the coolant level seem like things to try. Would a coolant replacement be in order? Maybe the fuel additive increased the effective octane level a bit and masked the issue. Any other easy things to look for?

As for the indy shop, I'm trying to do most of the work myself, but the alternator died in mid week and we didn't have time to wait until the weekend to get the car going again. We're looking for a third vehicle now so that we can have one briefly non-functional without drama.

[yspert]

the answer to all three of your questions is no. yspert

[yspert]

the answer to your other two questions is no. yspert

[mek42]

So am I SOL or do I need to keep thinking up more questions to ask?

What can cause an Echo to run rough and lose power given what I've stated?

[yspert]

Originally Posted by mek42

So am I SOL or do I need to keep thinking up more questions to ask?

What can cause an Echo to run rough and lose power given what I've stated?

yes, no, and 235,000 miles along with just about anything you can think of.
for it to have a drop in power, either the ign timing is changing (or a lack of spark), you are injecting too much or too little fuel (or at the wrong time), you are having a mechanical failure, or the mechanical timing is changing.
mechanical issues are not intermittent and typically are accompanied by noise. ignition and fuel issues can be intermittent and most of the time your problem will be found on the "spark" side. but, at your mileage and issues, it would be time for the fuel side to need attention. it could be anything. time to let it go or take the vehicle to someone who can fix it. yspert