Avalon - Endless Engine Sign Repairs Help!

My parent’s Toyota Avalon (1997)have gone to have a shop to get the engine sign repaired. But after going twice, the engine sign still appear and they are afraid the a 3rd or 4th time will be needed. Meaning they’re pouring more and more money into this issue without any confidence it will be fixed. What are my options to get this fixed?

1)Are my parent getting scammed by the shop or is this typical of engine sign problems?

2)Have they paid too much?

3)Can my parents tell them they’re not paying a penny more and demand the problem be fix? Is this reasonable?

Here’s the breakdown for the shop’s work:


R&R Intake - $225 (labor)

Manifold and Replace Knock Sensors - $400 (parts)

Gasket Set - $160 (parts)

TOTAL: $785


Replace A/F Sensor - $37 (labor)

A/F Sensor - $212 (parts)

TOTAL: $249


Without a description of the symptoms that prompted each of those repairs, and without the OBD2 trouble codes that prompted each repair, it is virtually impossible to comment.

You will have to give us MUCH more information.

How do I find the code? Is this something I have to ask the mechanic for?

I just spoke to the mechanic and he said that there was a OBD2 code for the initial fix and that there was a different code the second time. The second code was EGR flow related.

We’re going to go in for a third time and I’ll have him write down the exact code.

It sounds like bad or terrible diagnosis of problem instead of scamming.

Get an estimate to fix before proceeding further. And then negotiate hard.

Many auto parts chain stores (such as Autozone) will read the codes for free. They are in the format P0123. Get the codes read and post the exact codes here.

Ask the mechanic for the exact codes that came up the first time and then the second time.

Unfortunately he didn’t write down the codes but he told me the first one was something related to burn and clean.

We’ll probably ask for the code and get a estimate before proceeding any further (as suggested). We fear that the mechanic will charge for this 3rd fix but it doesn’t actually get fixed, and the cycle repeats.

Here are the codes for the 2nd and 3rd visitations.

12/22/09 - P0330
1/6/10 - P0401

The mechanic wasn’t able to give a cost estimate b/c he needs more closely inspect the vehicle.

So the question nows is whether or not this problem is something that takes several fixes to resolve or is it not something difficult to fix? Based on the trouble codes, are my expenses reasonable or not?

Thanks for the help!

The P0330 is a knock sensor circuit malfunction
The P0401 is an EGR valve flow insufficient

From these two codes I’d submit that the problem might be the EGR valve or its activating solenoid (perhaps a vacuum solenoid).

One of the things the EGR system does is prevent pinging. Pinging is what the knock sensor senses. Why it would show up as a code for a bed knock sensor circuit I do not know, unless bothe the EGR valve and the knock sensor were bad…but they just changed the knock sensors.

I don’t believe the repairs done were valid. Like others here, I suspect they’re guilty of lazy (or inept) troubleshooting.

Does this car require an emissions test? If so, when?

Until then, a .39 cent roll of black tape will cure all your problems…

Whats the recommendations to go forward with? Go back to the mechanic and get an estimate from or find another mechanic?

12/18/09 - Mechanical Work - Remove and replace intake manifold and both knock sensors - $785.00

12/22/09 - P0330 - Knock Sensor 2 Circuit Malfunction

12/30/09 - Mechanic’s response - Replace A/F sensor for $250.00???

01/06/10 - P0401 - EGR Insufficent Flow Detected

I suggest you find a different mechanic. The work on 12/30/09 was very possibly unnecessary and maybe a cover to get more money from a possible warranty repair. I believe he wanted to get some money for replacing a bad knock sensor, or maybe the wire simply fell off. I cannot comment on the work done on 12/18, because we have nothing else to go by.

The new code may be popping up due to a bad EGR or a simple clogged up tube. This needs to be properly diagnosed before ordering parts. Unfortunately, this is one of those codes a mechanic can make a lot of money replacing the EGR and related parts whether they need to be or not. It will fix the problem, but these parts can be expensive, especially with the shop mark-up. I’m guessing close to $400 in parts alone. Also unfortunately, getting an estimate is almost worthless, because until you take things apart and inspect/test them will you know what needs to be replaced or simply cleaned. This code can be triggered by a simple vacuum leak that $1.00 worth of vacuum hose can fix. I’m not saying that’s your problem, I’m just giving an example.