Cadillac Catera and Cimarron Forum Discussion, P0411 Air Injection Incorrect Flow in Past Cadillac Vehicle Discussion; My 2000 Catera Sport has a P0411 Air Injection Icorrect flow code.When car is cold started the AIR system works.If ...
My 2000 Catera Sport has a P0411 Air Injection Icorrect flow code.When car is cold started the AIR system works.If the hose betwen Shutoff valve and check valve is disconected with Air system working, there is a lot of air comming out of Shutoff valve.If shop air is injected thru the Check valve, it goes inside the manifolds (you can see the numbers on"short term fuel trim" on both banks going really high 18 to 23 %)this means the air-fuel mixture gets very lean because Air is entering the exahust manifolds.
The Computer "looks" at Short term fuel trims changes to diagnose AIR system,it knows if air is entering the manifods,but in this case a scanner was conected and when monitored the short term fuel trims noticed that they stay at 0% while the Air pump runs.Then the pump stops and short term trims start fluctuating close to - +0%.I don't undrestand how it can trow that code when I know for a Fact that lot of air is entering Exahust maniflods.Any Help?
I just got this code late last week, and i've gotten it before. And I'm begining to see a pattern as far as I've noticed is I typically get this code when ever the air is real dense. Last weekend it was really humid and the air was heavy. Started the car, turned on the a/c right away, and my check engine light come on. Took it to autozone and it was the p0411 again. Two days later the light went out by itself, just like last time. Everything works like it's suppose to, no cracks or loose lines to be found. I just ignore it. It's only emissions anyways. But there have been some members here that have gone a bit more into detail with finding fixes. But it in no way affects the performance of the engine.
Here in NY, you're required to have your car inspected yearly for safety and emissions. Older cars get the roller dyno with tailpipe sniffer. On 96+ cars that requires you have your OBD2 port scanned and checked for any DTC codes. If anything is activating the CEL then you fail, and if more than one "readiness code" isn't ready yet then you fail. Every time you have your car inspected here the mileage and whether you passed or failed safety and/or emissions is electronically reported to the DMV. Cars are registered on a 2 year basis, newly registered vehicles get a 10 day temporary inspection pass. If you don't pass within the 2 years then you cannot renew your registration until the car passes inspection. That said...
When I bought my Catera, I had a whole gang of codes coming up. They were all relatively easy fixes but the one that kept coming back was the P0411. I tricked the car into passing by clearing the codes and driving around a few miles, the secondary air injection was the only readiness section not completed as I pulled into the inspection station. I legally passed the emissions test but later that day the CEL came back on for the P0411. I tested the pump and it wasn't working at all. Searching online I found that the Catera's SAI pump was nearly impossible to find except a few used ones in the $500-$900 range. Searching these forums for a couple hours I finally found a relevant thread to the problem with a fix. Some sort of BMW's in the mid-late 90s used the same basic pump aside from the mounting cage and electrical pump. The hoses were also slightly different but adaptable.
I looked on eBay and found a Land Rover LR2 or maybe LR3 pump, knowing BMW owns Land Rover and the pump looking near identical I took my chance on it. Sure enough the dimensions were the same aside from a few small details. Luckily the seller had included both hoses as well. I combined parts of my broken pump with the Land Rover pump and put it all back together into the car. Ever since then it has worked great and I no longer get any codes related to the SAI system. Now I don't have to worry when inspection time comes around again.
Thanks for the info and input from all,just a reminder to all, my pump works.My mechanic replaced the :relay,pump,check valve and shut off valve solenoid.(yes I have 2 of each of these)The thing that confuses me is that AIR system description and operation states that "PCM monitors the short trim to diagnose AIR system"and my short fuel trims stay at 0% while pump runs.
Maybe someone can connect a scanner and look at "short term fuel trim" values when vehicle is cold started and post results...but that's probably too much to ask.Thank You all.