This is a kind of long story about my Monte's P0410 Check Engine Light and the ensuing repair process.

I recently had a problem with a P0410 CEL on the Monte. This is the second time in a little over a year. For those that have been lucky enough to have avoided this, it is a failure of

the Secondary Air Injection System. The first time it happened was October 2012. Being as this (was) my wife's daily driver I could not take the time to figure this out so I took it to

the Chevy dealer that has been servicing the car (oil changes and all) since we purchased it. At that time they replaced the Secondary Air Pump and Secondary Air Valve to the tune

of $650. Oh well, its the cost of maintenance. I also had them do some other work at the same time so the bill was closer to $1K.

Anyway, fast forward to December 6, 2013 and the CEL is back on. Run over the great folks at the local Advanced Auto and find that it is a P0410 again. Made and appointment

and dropped it off back at the dealer. Next day get a call that the pump and valve need to be replaced again. WHAT!? In addition the service writer tells me that the intake is

seeping as well as the oil pan and steering rack. Just for fun I asked how much to fix it all... $3500. Yeah, NO. I told him to fix the pump and valve and I'm NOT paying $650 again.

It's been 14 months, give me a break. I get the same old story about the water in the pump and I should make a shield. WHY! The first one lasted 10 years!

In the end they agreed to do the job for $100 even though they should have done it for free. The car did not even make it all the way home before the CEL was on again. UGH.

Call the dealer, take it back in a couple of days later and find out they did not replace the valve, just the pump. Thanks for the inconvenience. They put on a new valve while we

waited and we were on our way. Before this second visit, through the miracle of the Interweb I discovered that there is a TSB from 2004 for this very issue and that they should

have installed a shield, hose and filter to prevent water intrusion into the pump. It should have been done during the 2012 repair. They even argued with me a bit when I gave them

my printout of the TSB but then admitted that they would need to order the parts (I declined for them to do it). It was then and there I decided that my dealer loyalty meant nothing

and that I could not take a chance of the Monte failing (not that it would) and leaving my wife stuck somewhere. We purchased a replacement car and I decided to keep the Monte

for myself as an extra "hobby" car.

Well I used it for work last week and upon "spirited" acceleration I noticed what sounded like and exhaust leak. Then BAM the CEL was back on. WOW only 600 miles and it

was back on. I'm done bothering Advanced Auto and not buying stuff so I got a scan tool from Harbor Freight. To no surprise the P0410 was back. I cleared the code and it stayed

off for the next few days but I figured it wasn't right because a pending P0410 was stored. No more dealer trips for this car so now that I can take my time with it I decided to figure

out the real problem.

The pump is easy to access after removing the left headlight. I pulled the hoses and fired up the car but the pump did not run. It is supposed to run for about a minute upon first

starting. What was weird is that the hose from the SAI valve was pumping exhaust. Rev it up and I found my "exhaust leak". Still didn't answer why the pump didn't run. Checked

the fuse it the lower box near the battery and it was blown. Well that's special. I wonder if the dealer even checked it. Giving them the benefit of the doubt, I think the exhaust

condensed in the pump and it froze in the -0 degree weather and the fuse popped. At least I kind of had it figured out so I pulled the pump and tested it with jumper wires and it

worked great.

So what's up with this valve? I pulled the vacuum hose from the valve and the exhaust leak seemed to stop. I put it back and there was not much change but it did not seem right. A

check with a gauge showed 10" Hg when the system was inactive and 20" Hg active. That's not right so I pulled the vacuum solenoid valve which appears to be made from

unobtanium checked it electrically and cleaned it. I also checked which of the 2 ports vented to atmosphere. Upon re-installation THE SAME WAY IT WAS REMOVED I found

the hoses hooked up BACKWARDS. So in reality, the valve always had residual vacuum and the engine always had a slight vacuum leak. Upon reversing the hoses and checking

the operation with the gauge, vacuum on the valve went to 0 when the AIR system deactivated. I don't know if this was from the most recent repair or from the 2012 repair but it is

fixed now.

The takeaway for me from this adventure is:
*Dealer service after the warranty period is not that important. I realize they are in business to make money but don't screw me over with shoddy repairs and try to make me pay

twice. I don't know that I really extended the service life of this vehicle as opposed to just doing my own oil changes and letting the local mechanic fix the difficult stuff.
*This particular repair was not that difficult. The pump can be replaced with minimal tools in 15 minutes. The valve is only slightly more difficult.
*The parts for the repair can be easily sourced from Rock Auto or other online stores at a huge savings.
*Make sure the vacuum hoses are correctly installed on the AIR valve.

While the dealership was friendly and clean I will not be going back there for anything. Its not only for this repair issue but also for the intake issue I mentioned earlier. On their

recommendation I had them replace the intake gaskets because they apparently are prone to leaking coolant into the oil. Not the case on mine but I figured better safe than sorry.

My problem is they removed the intake and now its "seeping" 2 years and 12K miles later and I have to pay to fix it. At least the factory installation made it to 80K without issue.

Thanks anyway I will be doing it myself.

Regards
SteveB

 

Sorry for the formatting, I did a copy and paste from Notepad.

 

Hi `Steve,
Sorry to read about your problems with your former dealership. It is great that you have automotive knowledge. Thanks for sharing with your Monte Carlo Family on what problems you encountered.

Sadly, some lessons in life are more expensive then others. We live & hopefully learn not to repeat the bad ones. Good Luck to you & your Monte Carlo

 

WOW! First, great job out of getting out from under a loop that was not working. Even better, ending up solving it yourself with some time, study and research! Despite the problems, I'm sure you feel accomplished for being the one to finally lay this issue to bed!!

Second, you are right, that the LIM gaskets should not be leaking again after 12K miles. Makes me question the install. If you end up replacing them again, I recommend sourcing the metal replacements (get rid of the plastic/nylon ones).

Hopefully no more issues for a long time!!

 

Thanks lots for taking the time to tell us all that!


I have a CEL on my 2002 SS Monte Carlo,...with 2 codes,....one is the p0410.
I need to look into what's involved in checking the air pump, the valve and fuse. I know where I can find the fuse now!


Any tips to help fix my situation would be greatly appreciated!
Trying to see if I can fix it myself with a little research.
Thanks again!