1990 240SX Emissions problems.

[Alfador]

I took my car in for a MA state inspection in august, it failed for NOx on the emissions. (the car was relatively new for me at the time). So I dug around in the engine bay and found out that a bunch of the vac. system hoses had been bypassed (specifically the ones to the canister), so I got new hoses, checked the rest for leaks, and fixed that all up. come about 45 days later I had it inspected again (I go to college about 3 hrs from home and am usually seperated from either the car or the resources to work on it). The second inspection failed for NOx as well. I have the exact figures here...HC - 0.57CO - 8.99N0x - 3.63 (the limit for this was 3.0)I finally caved in and had a diagnostic done, and here's what they gave me for a report...

Quote »Tested emission and EVAP system. Hooked pressure up to EGR system. Found that EGR valve was working but solenoid to the valve was not. Recommend new solenoid and recheck system for inspection. [/quote]Not that all seems right, but the problem is they want $207 for parts and labor. Its the second part of this that really irks me though...Quote »Because engine has had several modifications it would be difficult to say if this repair will pass emissions level requirements and fix the problem.[/quote]This confuses me because its the original KA24E and the only modifications to it at all are an injen intake, and I was told by the previous owner that the EGR valve itself was replaced with a new OEM one about a year and a half ago because the old one was sticking.

I guess my real questions are 1. Does that all sound right? The modification comment makes me wonder...2. Is that price anywheres near normal?3. Would it be worth it to order the part and do the work myself?

Thanks in advance

EDIT: the only other mods are an exaust (all after the cat. cat itself and all parts between it and engine are original) and some body/suspension stuff.

Also, when I before I replaced the vaccum tubes and for a week or so after it Idled and started rough, but has smoothed out recently.
Modified by Alfador at 10:35 AM 4/2/2006

[NISTECH]

Egr is the primary control of nox. If the solonoid isnt working the egr does not do its job and you will have high nox. The disclaimer of the shop is neccessary since EGR BPT is control by exhuast system back pressure. The muffler contributes to that back pressure. If it flows to free you may not have enough back pressure in the system to close the BPT vent so the vaccum from the solonoid can get to the EGR to open it. They gave you the disclaimer since the back pressure is so important. They did however find a non functioning EGR component that needs to be replaced for sure. The dollar amount sounds about right maybe a little low on the labor side if the part is more then $50. At my nissan dealer we are $102 an hour labor rate. We charge a minium of an hour for engine diag. For smog failures we charge 2 hrs. 1 hr for a base line smog test since we do smog inspections, then we use the other hour to perform functional diagnostics. Now if we did the smog that failed the car we already have our base line so we dont need the first hour of time.

[Alfador]

In MA its real screwy, the inspection places almost never offer full diagnostics, and the diagnostic places usually dont to inspections anymore either. I think its because the state had some problems with places fudging readings just to get some extra labor pay. Either way the places that fail it never know what it might be, they just get the readings. They almost always shrug and say "could be the cat" no matter what the heck the problem is.

Anyways, I guess I'll go ahead with replacing the part, but I'm not going through them because I'm pretty sure I know someone who will put it in for either cost or really cheap labor. Just for the record, the $207 did not include the diagnostic. For some reason they only charge $72 for those and I paid that immediately upon completion.

Thanks a lot.

[NISTECH]

Do it yourself. The egr solonoid is located on you intake manifold toward the pasenger side kinda under the manifold. If you look down at the intake just infront of the strut tower you will see it. Just make sure you put the hoses back on the same ports they came off the old one.

[Alfador]

will do, I have the service manual w/ wiring and vacum diagrams so that should help a bit.